mychemistry 1.5 (23apr11)

git-svn-id: svn://tug.org/texlive/trunk@22176 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 560 insertions, 587 deletions

diff --git a/Master/texmf-dist/tex/latex/mychemistry/mychemistry.sty b/Master/texmf-dist/tex/latex/mychemistry/mychemistry.sty
index cf4ed6a2118..60a6b968d60 100644
--- a/Master/texmf-dist/tex/latex/mychemistry/mychemistry.sty
+++ b/Master/texmf-dist/tex/latex/mychemistry/mychemistry.sty
@@ -4,7 +4,7 @@
 % - Creating reaction schemes with LaTeX and ChemFig ---------------------------------- %
 % ------------------------------------------------------------------------------------- %
 % - Clemens Niederberger -------------------------------------------------------------- %
-% - 2011/04/15 ------------------------------------------------------------------------ %
+% - 2011/04/23 ------------------------------------------------------------------------ %
 % ------------------------------------------------------------------------------------- %
 % - http://www.niederberger-berlin.net/2011/02/latex-mychemistry/ --------------------- %
 % - kontakt@niederberger-berlin.net --------------------------------------------------- %
@@ -92,38 +92,53 @@
 % -   own arrow tips defined                                                          - %
 % -   command \setarrowline added                                                     - %
 % -   new arrow type -+> added                                                        - %
+% - 2011/04/23 version 1.5                                                            - %
+% -   major parts of the code rewritten --                                            - %
+% -     the whole positioning part now is different and way more flexible:            - %
+% -     arbitrary angles can be used for positioning, referencing an object is        - %
+% -     easier, arrows can be modified using <tikz>, command \anywhere now has        - %
+% -     similar syntax                                                                - %
+% -   arrow types <=>> and <<=> added                                                 - %
+% -   arrow type -+> modified: more flexible                                          - %
+% -   bugfixes in error-handling                                                      - %
 % ------------------------------------------------------------------------------------- %
-% - TODO                                                                              - %
+% - TODO:                                                                             - %
 % -   work on how chemistry-packages are automatically loaded;                        - %
 % -     add ui for easy handling this issue? (via \mCsetup ?)                         - %
-% -   add rotate=<winkel> for diagonal arrows?                                        - %
-% -   option for baseline-alignment of reactants et.al.?                              - %
-% -   option for shifting arrows?                                                     - %
-% -   Hook, damit die Befehle erkennen, ob sie innerhalb Umgebung sind?               - %
-% -   Pfeil-Typen: <<=>/<=>> hinzufügen                                               - %
+% -   add arrow types <=+>, <+=>, <=+>>, <+=>>, <<=+>, <<+=> ?                        - %
 % ------------------------------------------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\def\mC@def#1{%
-  \ifdefined#1%
-    \errmessage{myChemistry Package Error: the macro \string#1\space is already defined. Please let the author know.}%
-  \fi
-  \def#1%
-}
-\mC@def\mC@version{1.4}
-\mC@def\mC@date@de{15. April 2011}
-\mC@def\mC@date@en{April 15th 2011}
-\mC@def\mC@date{2011/04/15}
-\mC@def\mC@name{myChemistry}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Paket Info                                                                            %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\def\mC@version{1.5}
+\def\mC@date@de{23. April 2011}
+\def\mC@date@en{April 23rd 2011}
+\def\mC@date{2011/04/23}
+\def\mC@name{myChemistry}
 \ProvidesPackage{mychemistry}[\mC@date\space v\mC@version]
 \typeout{}
 \typeout{\mC@name\space v\mC@version}
 \typeout{\mC@date\space Clemens Niederberger}
 \typeout{}
 \RequirePackage{ifthen,calc,float,xkeyval}
+% myChemistry Informationen ----------------------------------------------------------- %
+\def\mCversion{\mC@version}
+\def\mCdate#1{\csname mC@date@#1\endcsname}
+% additional für ChemFig v0.4 --------------------------------------------------------- %
+\def\mC@CFversion@test{0.4}%
+\IfFileExists{bondwidth.tex}{%
+  \ifx\CF@ver\mC@CFversion@test\input{bondwidth}\fi
+}{}%
+\def\mC@CFversion@test{0.4a}
+\IfFileExists{bondwidth.tex}{%
+  \ifx\CF@ver\mC@CFversion@test\input{bondwidth}\fi
+}{}%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Optionen, z.T. auch an chemexec weitergeben
-\mC@def\mC@exec@color{black}
-\mC@def\mC@exec@shade{false}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\def\mC@exec@color{black}
+\def\mC@exec@shade{false}
 \newif\if@usecolor\@usecolorfalse
 % wenn key color, dann Farbe und Option shade=true an chemexec weitergeben
 \define@key[MC]{mychemistry.sty}%
@@ -143,22 +158,22 @@
   \def\mC@exec@shade{true}
 }
 % chemexec abschalten
-\mC@def\mC@exec@true{true}
+\def\mC@exec@true{true}
 \DeclareOptionX[MC]{nochemexec}{%
   \def\mC@exec@true{false}
 }
 % mhchem abschalten
-\mC@def\mC@mhchem@true{true}
+\def\mC@mhchem@true{true}
 \DeclareOptionX[MC]{nomhchem}{%
   \def\mC@mhchem@true{false}
 }
 % chemcompounds abschalten
-\mC@def\mC@compound@true{true}
+\def\mC@compound@true{true}
 \DeclareOptionX[MC]{nocompounds}{%
   \def\mC@compound@true{false}
 }
 % chemstyle einschalten
-\mC@def\mC@chemstyle@true{false}
+\def\mC@chemstyle@true{false}
 \DeclareOptionX[MC]{chemstyle}{%
   \def\mC@chemstyle@true{true}
 }
@@ -170,14 +185,14 @@
   \def\mC@chemstyle@true{false}
 }
 % englische Version von chemexec, englische Variante von myChemistry
-\mC@def\mC@exec@english{}
-\mC@def\mC@rs@name{Reaktionsschema}
+\def\mC@exec@english{}
+\def\mC@rs@name{Reaktionsschema}
 \DeclareOptionX[MC]{english}{
   \def\mC@exec@english{,english}
   \def\mC@rs@name{Reaction scheme}
 }
-\mC@def\mC@rs@placement{H}
-\mC@def\mC@rs@currentplacement{\mC@rs@placement}
+\def\mC@rs@placement{hpt}
+\def\mC@rs@currentplacement{\mC@rs@placement}
 \define@key[MC]{mychemistry.sty}{placement}{
   \def\mC@rs@placement{#1}
 }
@@ -211,7 +226,7 @@
   }
   \usetikzlibrary{arrows,positioning,decorations.pathmorphing,shapes,calc,matrix,chains,scopes}
 }{% sonst Fehlermeldung
-  \PackageError{mychemistry}{`ChemFig' is not installed! `myChemistry' can't work without it!}
+  \PackageError{mychemistry}{The ChemFig package is not installed! myChemistry can't work without it}{See the myChemistry package documentation for explanation}
 }
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % chemexec laden, falls verfügbar, falls nicht, dann wenigstens mhchem laden
@@ -238,271 +253,332 @@
 }
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% NEUE BEFEHLE:                                                                         %
+% Tools ------------------------------------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% myChemistry Informationen ----------------------------------------------------------- %
-\mC@def\mCversion{\mC@version}
-\mC@def\mCdate#1{\csname mC@date@#1\endcsname}
-% additional für ChemFig v0.4 --------------------------------------------------------- %
-\mC@def\mC@CFversion@test{0.4}%
-\IfFileExists{bondwidth.tex}{%
-  \ifx\CF@ver\mC@CFversion@test\input{bondwidth}\fi
-}{}%
-\def\mC@CFversion@test{0.4}
-\IfFileExists{bondwidth.tex}{%
-  \ifx\CF@ver\mC@CFversion@test\input{bondwidth}\fi
-}{}%
+\def\mC@true{true}
+\def\mC@false{false}
 % Optional Argument Analysis ---------------------------------------------------------- %
 % Prüfen ob #2 in #1 enthalten ist
-\mC@def\mC@if@instr#1#2{%
+\def\mC@if@instr#1#2{%
   \def\mC@if@instr@i##1#2##2\@nil{\ifx\@empty##2\@empty\expandafter\@secondoftwo\else\expandafter\@firstoftwo\fi}%
   \mC@if@instr@i#1\@@nil#2\@nil
 }
 % Am ersten , splitten, #1 in #3 speichern, #2 in \mC@remainargs
-\mC@def\mC@splitfirst#1,#2\@nil#3{%
+\def\mC@splitfirst#1,#2\@nil#3{%
   \def#3{#1}\def\mC@remainargs{#2}%
 }
 % ein durch , in 3 Teile getrenntes Argument splitten
-\mC@def\mC@splitarg#1{
+\def\mC@splitarg#1{
   \mC@if@instr{#1}{,}{\expandafter\mC@splitfirst#1\@nil\mC@firstarg}{\def\mC@firstarg{#1}}
   \expandafter\mC@if@instr\expandafter{\mC@remainargs}{,}{\expandafter\mC@splitfirst\mC@remainargs\@nil\mC@secondarg}{\expandafter\def\expandafter\mC@secondarg\expandafter{\mC@remainargs}}
   \ifx\mC@remainargs\mC@secondarg\let\mC@thirdarg\@empty\else\expandafter\def\expandafter\mC@thirdarg\expandafter{\mC@remainargs}\fi
 }
+% Direction Analysis ------------------------------------------------------------------ %
+% Richtungen:
+\def\mC@r{right}
+\def\mC@ar{above right}
+\def\mC@a{above}
+\def\mC@al{above left}
+\def\mC@l{left}
+\def\mC@br{below right}
+\def\mC@b{below}
+\def\mC@bl{below left}
+\def\mC@vert@i{90}
+\def\mC@vert@ii{-90}
+\def\mC@vert@iii{270}
+% Richtung in Bezug auf node oder nicht? 
+\def\mC@split@angle#1.#2\@nil#3{\def#3{#1}\def\mC@direction{#2}}
+\def\mC@wowo@node#1{\mC@if@instr{#1}{.}{\expandafter\mC@split@angle#1\@nil\mC@referred@node}{\def\mC@direction{#1}}}
+% Winkel bestimmen:
+\def\mC@analyze@angle#1{
+  \let\mC@angle\@empty
+  \let\mC@referred@node\@empty
+  \mC@wowo@node{#1}
+  \ifx\mC@direction\mC@r\def\mC@angle{0}\fi
+  \ifx\mC@direction\mC@ar\def\mC@angle{45}\fi
+  \ifx\mC@direction\mC@a\def\mC@angle{90}\fi
+  \ifx\mC@direction\mC@al\def\mC@angle{135}\fi
+  \ifx\mC@direction\mC@l\def\mC@angle{180}\fi
+  \ifx\mC@direction\mC@bl\def\mC@angle{225}\fi
+  \ifx\mC@direction\mC@b\def\mC@angle{270}\fi
+  \ifx\mC@direction\mC@br\def\mC@angle{315}\fi
+  \ifx\mC@angle\@empty\pgfmathparse{\mC@direction <0 ? int(\mC@direction+360) : int(\mC@direction) }\edef\mC@angle{\pgfmathresult}\fi
+}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % PFEILE ------------------------------------------------------------------------------ %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% interne Befehle, Voreinstellungen --------------------------------------------------- %
-\mC@def\mC@arrow@above{above}                    % oben
-\mC@def\mC@arrow@currentabove{\mC@arrow@above}   %
-\mC@def\mC@arrow@below{below}                    % unten
-\mC@def\mC@arrow@currentbelow{\mC@arrow@below}   %
-\mC@def\mC@arrow@direction{right}                % Richtung
-\mC@def\mC@arrow@currentdirection{\mC@arrow@direction}
-\mC@def\mC@arrow@currentlength{\mC@arrow@length}
-\newlength{\mC@arrow@length@actual}
-\mC@def\mC@arrow@rotate{}
-\mC@def\mC@arrow@argument@angle{}
-\mC@def\mC@arrow@argument@shift{2pt}
-\mC@def\mC@arrow@argument@anchor{}
-\mC@def\mC@arrow@argument@both{}
-\mC@def\mC@arrow@above@anchor{}
-\mC@def\mC@arrow@below@anchor{}
-\mC@def\mC@arrow@type{->}                        % Pfeiltyp
-\mC@def\mC@arrow@currenttype{\mC@arrow@type}     %
-\mC@def\mC@arrow@start@up{0,0.05}                % Verschiebung für Glgw-Pfeil
-\mC@def\mC@arrow@start@down{0,-0.05}             %
-\mC@def\mC@arrow@placement{on chain=going \mC@arrow@currentdirection} % wohin?
-\mC@def\mC@arrow@currentplacement{\mC@arrow@placement}
-\mC@def\mC@arrow@cross@base@x{}                  % Befehle für durchgestrichenen Pfeil
-\mC@def\mC@arrow@cross@base@y{}                  %
-\mC@def\mC@arrow@cross@angle{}                   %
-\mC@def\mC@arrow@cross@length{}                  %
-\mC@def\mC@arrow@cross@draw{}                    %
+% \arrow[<pos>,<type>,<length factor>,<name>,both,<tikz>]{<above>}{<below>}
+% Pfeiltypen:
+\def\mC@arrow@type@def{->}
+\def\mC@arrow@type@eqv{<->}
+\def\mC@arrow@type@back{<-}
+\def\mC@arrow@type@eq{<=>}
+\def\mC@arrow@type@eqq{<=>>}
+\def\mC@arrow@type@eeq{<<=>}
+\def\mC@arrow@type@not{-|>}
+\def\mC@arrow@type@pm{-+>}
 
-% Laengenfaktor ----------------------------------------------------------------------- %
-\mC@def\mC@arrow@length{1.0}                     % Längenfaktor
-\mC@def\mC@arrow@length@factor{1.0}              % Default-Faktor
-\mC@def\mC@arrow@end{\mC@arrow@length@actual,0}  % Pfeilende
-\define@key{arrow}{length}[\mC@arrow@length]{%   %
-  \renewcommand{\mC@arrow@currentlength}{#1}}%   %
-\newlength{\mC@arrow@length@default}             %
-\setlength{\mC@arrow@length@default}{5em}        %
-\newlength{\mC@arrow@length@value}               %
-\setlength{\mC@arrow@length@value}{\mC@arrow@length@default} % Default-Laenge
-\mC@def\setarrowlength#1{
- \ifx\@empty#1\@empty
-  \setlength{\mC@arrow@length@value}{\mC@arrow@length@default}
- \else
-  \setlength{\mC@arrow@length@value}{#1}
- \fi
-}
-% \let\arrowlength\setarrowlength
-
-% Beschriftungen ---------------------------------------------------------------------- %
-\newlength{\mC@arrow@argument@aboveshift}        % Verschieben der Beschriftung
-\newlength{\mC@arrow@argument@belowshift}        % Verschieben der Beschriftung
-\define@key{arrow}{aboveshift}[2pt]{%
-  \setlength{\mC@arrow@argument@aboveshift}{#1}}
-\define@key{arrow}{belowshift}[2pt]{%
-  \setlength{\mC@arrow@argument@belowshift}{#1}}
-\define@key{arrow}{both}[]{
-  \renewcommand{\mC@arrow@argument@both}{true}
+% Voreinstellungen -------------------------------------------------------------------- %
+% Pfeillänge -------------------------------------------------------------------------- %
+% \newlength{\mC@arrow@length}
+\def\mC@arrow@length@def{4em}
+\let\mC@arrow@length\mC@arrow@length@def
+\def\mC@arrow@factor{1}
+\def\setarrowlength#1{%
+  \ifx\@empty#1\@empty%
+    \let\mC@arrow@length\mC@arrow@length@def%
+  \else%
+    \def\mC@arrow@length{#1}%
+  \fi%
 }
-
-% Anker ------------------------------------------------------------------------------- %
-\mC@def\mC@arrow@name{}                          % Anker
-\mC@def\mC@arrow@currentname{\mC@arrow@name}     %
-\define@key{arrow}{name}[\mC@arrow@name]{%       %
-  \renewcommand{\mC@arrow@currentname}{#1}}%     %
-
-% Richtung ---------------------------------------------------------------------------- %
-\define@key{arrow}{direction}[\mC@arrow@direction]{%
-    \renewcommand{\mC@arrow@currentdirection}{#1} %
-    \ifthenelse{\equal{#1}{right}}{% nach rechts, Einstellungen:
-     \renewcommand{\mC@arrow@end}{\mC@arrow@length@actual,0}
-     \renewcommand{\mC@arrow@currentabove}{above}
-     \renewcommand{\mC@arrow@currentbelow}{below}
-     \renewcommand{\mC@arrow@above@anchor}{south}
-     \renewcommand{\mC@arrow@below@anchor}{north}
-     \renewcommand{\mC@arrow@argument@anchor}{
-       \node(@arrow@center) at ($(\tikzchainprevious.east)+(.5\mC@arrow@length@actual+\mC@rxn@node@distance,0)$) {};
-     }
-     \renewcommand{\mC@arrow@argument@angle}{0}
-     \renewcommand{\mC@arrow@rotate}{0}
-     \renewcommand{\mC@arrow@start@up}{0,0.03}
-     \renewcommand{\mC@arrow@start@down}{0,-0.03}
-     \renewcommand{\mC@arrow@cross@base@x}{.15em}
-     \renewcommand{\mC@arrow@cross@base@y}{0}
-     \renewcommand{\mC@arrow@cross@angle}{60}
-     \renewcommand{\mC@arrow@cross@length}{.5em}
-    }{
-     \ifthenelse{\equal{#1}{above right}}{% nach oben rechts, Einstellungen:
-      \renewcommand{\mC@arrow@end}{\mC@arrow@length@actual,\mC@arrow@length@actual}
-      \renewcommand{\mC@arrow@currentabove}{above left}
-      \renewcommand{\mC@arrow@currentbelow}{below right}
-      \renewcommand{\mC@arrow@above@anchor}{south}
-      \renewcommand{\mC@arrow@below@anchor}{north}
-      \renewcommand{\mC@arrow@argument@anchor}{
-        \node(@arrow@center) at ($(\tikzchainprevious.north east)+(.5\mC@arrow@length@actual+.707\mC@rxn@node@distance,.5\mC@arrow@length@actual+.707\mC@rxn@node@distance)$) {};
-      }
-      \renewcommand{\mC@arrow@argument@angle}{45}
-      \renewcommand{\mC@arrow@rotate}{45}
-      \renewcommand{\mC@arrow@start@up}{-0.02,0.02}
-      \renewcommand{\mC@arrow@start@down}{0.02,-0.02}
-      \renewcommand{\mC@arrow@cross@base@x}{.1em}
-      \renewcommand{\mC@arrow@cross@base@y}{.1em}
-      \renewcommand{\mC@arrow@cross@angle}{-15}
-      \renewcommand{\mC@arrow@cross@length}{.7em}
-     }{
-     \ifthenelse{\equal{#1}{above}}{% nach oben, Einstellungen:
-      \renewcommand{\mC@arrow@end}{0,\mC@arrow@length@actual}
-      \renewcommand{\mC@arrow@currentabove}{left}
-      \renewcommand{\mC@arrow@currentbelow}{right}
-      \renewcommand{\mC@arrow@above@anchor}{east}
-      \renewcommand{\mC@arrow@below@anchor}{west}
-      \renewcommand{\mC@arrow@argument@anchor}{
-       \node(@arrow@center) at ($(\tikzchainprevious.north)+(0,.5\mC@arrow@length@actual+\mC@rxn@node@distance)$) {};
-      }
-      \renewcommand{\mC@arrow@argument@angle}{90}
-      \renewcommand{\mC@arrow@rotate}{0}
-      \renewcommand{\mC@arrow@start@up}{-0.03,0}
-      \renewcommand{\mC@arrow@start@down}{0.03,0}
-      \renewcommand{\mC@arrow@cross@base@x}{0}
-      \renewcommand{\mC@arrow@cross@base@y}{.15em}
-      \renewcommand{\mC@arrow@cross@angle}{30}
-      \renewcommand{\mC@arrow@cross@length}{.5em}
-      }{
-       \ifthenelse{\equal{#1}{above left}}{% nach oben links, Einstellungen:
-        \renewcommand{\mC@arrow@end}{-\mC@arrow@length@actual,\mC@arrow@length@actual}
-        \renewcommand{\mC@arrow@currentabove}{above right}
-        \renewcommand{\mC@arrow@currentbelow}{below left}
-        \renewcommand{\mC@arrow@above@anchor}{south}
-        \renewcommand{\mC@arrow@below@anchor}{north}
-        \renewcommand{\mC@arrow@argument@anchor}{
-          \node(@arrow@center) at ($(\tikzchainprevious.north west)+(-.5\mC@arrow@length@actual-.707\mC@rxn@node@distance,.5\mC@arrow@length@actual+.707\mC@rxn@node@distance)$) {};
-        }
-        \renewcommand{\mC@arrow@argument@angle}{-45}
-        \renewcommand{\mC@arrow@rotate}{-45}
-        \renewcommand{\mC@arrow@start@up}{-0.02,-0.02}
-        \renewcommand{\mC@arrow@start@down}{0.02,0.02}
-        \renewcommand{\mC@arrow@cross@base@x}{-.1em}
-        \renewcommand{\mC@arrow@cross@base@y}{.1em}
-        \renewcommand{\mC@arrow@cross@angle}{15}
-        \renewcommand{\mC@arrow@cross@length}{.7em}
-       }{
-       \ifthenelse{\equal{#1}{left}}{% nach links, Einstellungen:
-        \renewcommand{\mC@arrow@end}{-\mC@arrow@length@actual,0}
-        \renewcommand{\mC@arrow@currentabove}{above}
-        \renewcommand{\mC@arrow@currentbelow}{below}
-        \renewcommand{\mC@arrow@above@anchor}{south}
-        \renewcommand{\mC@arrow@below@anchor}{north}
-        \renewcommand{\mC@arrow@argument@anchor}{
-          \node(@arrow@center) at ($(\tikzchainprevious.west)+(-.5\mC@arrow@length@actual-\mC@rxn@node@distance,0)$) {};
-        }
-        \renewcommand{\mC@arrow@argument@angle}{0}
-        \renewcommand{\mC@arrow@rotate}{0}
-        \renewcommand{\mC@arrow@start@up}{0,-0.03}
-        \renewcommand{\mC@arrow@start@down}{0,0.03}
-        \renewcommand{\mC@arrow@cross@base@x}{.15em}
-        \renewcommand{\mC@arrow@cross@base@y}{0}
-        \renewcommand{\mC@arrow@cross@angle}{60}
-        \renewcommand{\mC@arrow@cross@length}{.5em}
-       }{
-        \ifthenelse{\equal{#1}{below left}}{% nach unten links, Einstellungen:
-         \renewcommand{\mC@arrow@end}{-\mC@arrow@length@actual,-\mC@arrow@length@actual}
-         \renewcommand{\mC@arrow@currentabove}{above left}
-         \renewcommand{\mC@arrow@currentbelow}{below right}
-         \renewcommand{\mC@arrow@above@anchor}{south}
-         \renewcommand{\mC@arrow@below@anchor}{north}
-         \renewcommand{\mC@arrow@argument@anchor}{
-           \node(@arrow@center) at ($(\tikzchainprevious.south west)+(-.5\mC@arrow@length@actual-.707\mC@rxn@node@distance,-.5\mC@arrow@length@actual-.707\mC@rxn@node@distance)$) {};
-         }
-         \renewcommand{\mC@arrow@argument@angle}{45}
-         \renewcommand{\mC@arrow@rotate}{45}
-         \renewcommand{\mC@arrow@start@up}{0.02,-0.02}
-         \renewcommand{\mC@arrow@start@down}{-0.02,0.02}
-         \renewcommand{\mC@arrow@cross@base@x}{.1em}
-         \renewcommand{\mC@arrow@cross@base@y}{.1em}
-         \renewcommand{\mC@arrow@cross@angle}{-15}
-         \renewcommand{\mC@arrow@cross@length}{.7em}
-        }{
-         \ifthenelse{\equal{#1}{below}}{% nach unten, Einstellungen:
-          \renewcommand{\mC@arrow@end}{0,-\mC@arrow@length@actual}
-          \renewcommand{\mC@arrow@currentabove}{left}
-          \renewcommand{\mC@arrow@currentbelow}{right}
-          \renewcommand{\mC@arrow@above@anchor}{east}
-          \renewcommand{\mC@arrow@below@anchor}{west}
-          \renewcommand{\mC@arrow@argument@anchor}{
-            \node(@arrow@center) at ($(\tikzchainprevious.south)+(0,-.5\mC@arrow@length@actual-\mC@rxn@node@distance)$) {};
-          }
-          \renewcommand{\mC@arrow@argument@angle}{90}
-          \renewcommand{\mC@arrow@rotate}{0}
-          \renewcommand{\mC@arrow@start@up}{0.03,0}
-          \renewcommand{\mC@arrow@start@down}{-0.03,0}
-          \renewcommand{\mC@arrow@cross@base@x}{0}
-          \renewcommand{\mC@arrow@cross@base@y}{.15em}
-          \renewcommand{\mC@arrow@cross@angle}{30}
-          \renewcommand{\mC@arrow@cross@length}{.5em}
-         }{
-          \ifthenelse{\equal{#1}{below right}}{% nach unten rechts, Einstellungen:
-           \renewcommand{\mC@arrow@end}{\mC@arrow@length@actual,-\mC@arrow@length@actual}
-           \renewcommand{\mC@arrow@currentabove}{above right}
-           \renewcommand{\mC@arrow@currentbelow}{below left}
-           \renewcommand{\mC@arrow@above@anchor}{south}
-           \renewcommand{\mC@arrow@below@anchor}{north}
-           \renewcommand{\mC@arrow@argument@anchor}{
-             \node(@arrow@center) at ($(\tikzchainprevious.south east)+(.5\mC@arrow@length@actual+.707\mC@rxn@node@distance,-.5\mC@arrow@length@actual-.707\mC@rxn@node@distance)$) {};
-           }
-           \renewcommand{\mC@arrow@argument@angle}{-45}
-           \renewcommand{\mC@arrow@rotate}{-45}
-           \renewcommand{\mC@arrow@start@up}{0.02,0.02}
-           \renewcommand{\mC@arrow@start@down}{-0.02,-0.02}
-           \renewcommand{\mC@arrow@cross@base@x}{-.1em}
-           \renewcommand{\mC@arrow@cross@base@y}{.1em}
-           \renewcommand{\mC@arrow@cross@angle}{15}
-           \renewcommand{\mC@arrow@cross@length}{.7em}
-          }{
-           \PackageError{mychemistry}{Unknown arrow direction}% oder Fehler
-          }
-         }
-        }
-       }
-      }
-     }
-    }
-   }
+% Label-Abstand ----------------------------------------------------------------------- %
+\def\mC@arrow@label@dist@def{.2em}
+\def\mC@arrow@label@dist{\mC@arrow@label@dist@def}
+\def\setarrowlabel#1{%
+  \ifx\@empty#1\@empty%
+    \def\mC@arrow@label@dist{\mC@arrow@label@dist@def}%
+  \else%
+    \def\mC@arrow@label@dist{#1}%
+  \fi%
 }
-
 % Pfeildicke -------------------------------------------------------------------------- %
-\mC@def\mC@arrow@linethickness@default{semithick}
-\mC@def\mC@arrow@linethickness{\mC@arrow@linethickness@default}
-\mC@def\setarrowline#1{%
+\def\mC@arrow@linethickness@default{semithick}
+\def\mC@arrow@linethickness{\mC@arrow@linethickness@default}
+\def\setarrowline#1{%
   \ifx\@empty#1\@empty%
     \def\mC@arrow@linethickness{\mC@arrow@linethickness@default}%
   \else%
     \def\mC@arrow@linethickness{#1}%
   \fi%
 }
+% ------------------------------------------------------------------------------------- %
+% Winkel untersuchen, um Label richtig anzubringen ------------------------------------ %
+\def\mC@evaluate@angle#1{
+\newcount\mC@alpha
+\mC@alpha=#1
+\pgfmathparse{cos(\mC@alpha) > 0}
+\ifnum\pgfmathresult=1
+  \def\mC@beta{#1}
+  \def\mC@arrow@label@anchor@up{south}
+  \def\mC@arrow@label@anchor@down{north}
+  \ifnum\mC@alpha<180
+    \def\mC@arrow@label@anchor@add{east}
+    \def\mC@arrow@label@anchor@sub{south}
+  \else
+    \def\mC@arrow@label@anchor@add{south}
+    \def\mC@arrow@label@anchor@sub{west}
+  \fi
+\else
+  \pgfmathparse{cos(\mC@alpha) == 0}
+  \ifnum\pgfmathresult=1
+    \def\mC@beta{0}
+    \ifnum\mC@alpha=90
+      \def\mC@arrow@label@anchor@up{east}
+      \def\mC@arrow@label@anchor@down{west}
+      \def\mC@arrow@label@anchor@add{east}
+      \def\mC@arrow@label@anchor@sub{east}
+    \else
+      \def\mC@arrow@label@anchor@up{west}
+      \def\mC@arrow@label@anchor@down{east}
+      \def\mC@arrow@label@anchor@add{west}
+      \def\mC@arrow@label@anchor@sub{west}
+    \fi
+  \else
+    \def\mC@arrow@label@anchor@up{north}
+    \def\mC@arrow@label@anchor@down{south}
+    \ifnum\mC@alpha=180
+      \def\mC@beta{180-#1}
+      \def\mC@arrow@label@anchor@add{north}
+      \def\mC@arrow@label@anchor@sub{north}
+    \fi
+    \ifnum\mC@alpha>180
+      \def\mC@beta{180+#1}
+      \def\mC@arrow@label@anchor@add{west}
+      \def\mC@arrow@label@anchor@sub{north}
+    \fi
+    \ifnum\mC@alpha<180
+      \def\mC@beta{180+#1}
+      \def\mC@arrow@label@anchor@add{north}
+      \def\mC@arrow@label@anchor@sub{east}
+    \fi
+  \fi
+\fi
+}
+% ------------------------------------------------------------------------------------- %
+% Maße der Nodes der Pfeilargumente bestimmen, größere später an Pfeil weitergeben
+\def\mC@arrow@both{both}
+\newlength{\mC@height@A}
+\newlength{\mC@height@B}
+\newlength{\mC@arrow@label@height}
+\newlength{\mC@width@A}
+\newlength{\mC@width@B}
+\newlength{\mC@arrow@label@width}
+\def\mC@savenode{%
+    \global\let\mC@minx=\pgfpositionnodelaterminx%
+    \global\let\mC@maxx=\pgfpositionnodelatermaxx%
+    \global\let\mC@miny=\pgfpositionnodelaterminy%
+    \global\let\mC@maxy=\pgfpositionnodelatermaxy%
+}%
+% der nächste Befehl benötigt pgf v2.10!
+\def\mC@largernode#1#2{
+  \@ifundefined{pgfpositionnodelater}{
+    \PackageError{mychemistry}{The command \string\pgfpositionnodelater\space is undefined. Make sure, you have installed the latest version of pgf}{See the myChemistry package documentation for explanation}
+  }{}
+  {\pgfpositionnodelater{\mC@savenode}
+  \node{#1};
+  \setlength{\mC@width@A}{\mC@maxx}%
+  \addtolength{\mC@width@A}{-\mC@minx}
+  \setlength{\mC@height@A}{\mC@maxy}%
+  \addtolength{\mC@height@A}{-\mC@miny}
+  \node{#2};
+  \setlength{\mC@width@B}{\mC@maxx}%
+  \addtolength{\mC@width@B}{-\mC@minx}
+  \setlength{\mC@height@B}{\mC@maxy}%
+  \addtolength{\mC@height@B}{-\mC@miny}
+  \pgfmathsetlength{\mC@arrow@label@width}{max(\mC@width@A,\mC@width@B)}
+  \pgfmathsetlength{\mC@arrow@label@height}{max(\mC@height@A,\mC@height@B)}
+  \global\mC@arrow@label@width=\mC@arrow@label@width
+  \global\mC@arrow@label@height=\mC@arrow@label@height
+  }
+}
+% ------------------------------------------------------------------------------------- %
+% Pfeil zeichnen:
+\def\arrow{\@ifnextchar[{\mC@arrow@ii}{\mC@arrow@i}}
+\def\mC@arrow@i#1#2{
+ \node[on chain=going {at=(\tikzchainprevious.0)},minimum size=0,inner sep=3pt,outer sep=0,anchor=180,shift=(0:.5*\mC@rxn@node@distance)] (@mC@arrow@start){};
+ \node[on chain=going {at=(\tikzchainprevious.0),shift=($(0:.5*\mC@arrow@factor*\mC@arrow@length)$)}, minimum size=0,inner sep=3pt,outer sep=0] (@mC@arrow@end){};
+ \draw[-mCtip,\mC@arrow@linethickness] let \n1={0}, \n2={180} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](mC@arrow@center){} ++($(0:\mC@arrow@factor*\mC@arrow@length)$);
+ \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=0,anchor=south,inner sep=0] at ($(mC@arrow@center)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#1};
+ \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=0,anchor=north,inner sep=0] at ($(mC@arrow@center)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#2};
+}
+\def\mC@arrow@ii[#1]#2#3{
+ \let\mC@arrow@plusminus\@empty
+ \let\mC@arrow@type\@empty
+ \let\mC@remainargs\@empty\mC@splitarg{#1}
+ \ifx\@empty\mC@firstarg% erste Option: Richtung
+  \def\mC@angle{0}
+  \def\mC@beta{0}
+  \def\mC@arrow@label@anchor@up{south}
+  \def\mC@arrow@label@anchor@down{north}
+  \def\mC@arrow@label@anchor@add{south}
+  \def\mC@arrow@label@anchor@sub{south}
+  \def\mC@anchor{180}
+  \let\mC@referred@node\@empty
+ \else
+  \expandafter\mC@analyze@angle\expandafter{\mC@firstarg}
+  \def\mC@anchor{180+\mC@angle}
+  \mC@evaluate@angle{\mC@angle}
+ \fi
+ \ifx\mC@referred@node\@empty\def\mC@referred@node{\tikzchainprevious}\fi
+ \ifx\@empty\mC@secondarg\else% zweite Option: Typ
+  \def\mC@arrow@type{true}
+  \let\mC@arrow@type@actual\mC@secondarg
+ \fi
+ \let\mC@remainargs\@empty%
+ \expandafter\mC@splitarg\expandafter{\mC@thirdarg}%
+ \ifx\@empty\mC@firstarg% dritte Option: Längenfaktor
+  \def\mC@arrow@factor{1}%
+ \else%
+  \edef\mC@arrow@factor{\mC@firstarg}%
+ \fi%
+ \ifx\@empty\mC@secondarg% vierte Option: Name
+   \def\mC@arrow@name{mC@arrow@center}%
+ \else%
+   \edef\mC@arrow@name{\mC@secondarg}%
+ \fi%
+ \let\mC@remainargs\@empty%
+ \expandafter\mC@splitarg\expandafter{\mC@thirdarg}%
+ \ifx\mC@arrow@both\mC@firstarg% fünfte Option: both
+   \mC@largernode{#2}{#3}%
+ \else%
+   \setlength{\mC@arrow@label@width}{0pt}%
+   \setlength{\mC@arrow@label@height}{0pt}%
+ \fi%
+ \ifx\@empty\mC@secondarg% sechste Option: tikz
+   \let\mC@arrow@tikz\@empty%
+ \else%
+   \edef\mC@arrow@tikz{\mC@secondarg,\mC@thirdarg}%
+ \fi%
+ \node[on chain=going {at=(\mC@referred@node.\mC@angle)},minimum size=0,inner sep=3pt,outer sep=0,anchor=\mC@anchor,shift=(\mC@angle:.5*\mC@rxn@node@distance)] (@mC@arrow@start){};
+ \node[on chain=going {at=(\tikzchainprevious.\mC@angle),shift=($(\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$)}, minimum size=0,inner sep=3pt,outer sep=0] (@mC@arrow@end){};
+ \ifx\mC@arrow@type\mC@true
+   \let\mC@arrow@type@valid\mC@false%
+   \ifx\mC@arrow@type@actual\mC@arrow@type@eq% <=>
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,-mChtip,\mC@arrow@linethickness] let \n1={20+\mC@angle}, \n2={160+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](mC@arrow@center@up){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\draw\expandafter[\mC@arrow@tikz,mChtip-,\mC@arrow@linethickness] let \n1={-20+\mC@angle}, \n2={200+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](mC@arrow@center@down){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \draw[draw=none] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(mC@arrow@center@up)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+     \expandafter\node[\expandafter\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(mC@arrow@center@down)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@eqq% <=>>
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,-mChtip,\mC@arrow@linethickness] let \n1={20+\mC@angle}, \n2={160+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](mC@arrow@center@up){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\draw\expandafter[\mC@arrow@tikz,mChtip-,\mC@arrow@linethickness] let \n1={-20+\mC@angle} in ($(@mC@arrow@start.\n1)+(\mC@angle:.25*\mC@arrow@factor*\mC@arrow@length)$) --node[pos=.5,inner sep=0](mC@arrow@center@down){} ++($(\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$);
+     \draw[draw=none] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(mC@arrow@center@up)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+     \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(mC@arrow@center@down)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@eeq% <<=>
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,-mChtip,\mC@arrow@linethickness] let \n1={20+\mC@angle}, \n2={160+\mC@angle} in ($(@mC@arrow@start.\n1)+(\mC@angle:.25*\mC@arrow@factor*\mC@arrow@length)$) --node[pos=.5,inner sep=0](mC@arrow@center@up){} ++($(\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\draw\expandafter[\mC@arrow@tikz,mChtip-,\mC@arrow@linethickness] let \n1={-20+\mC@angle}, \n2={200+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](mC@arrow@center@down){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \draw[draw=none] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(mC@arrow@center@up)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+     \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(mC@arrow@center@down)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@def% ->
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,-mCtip,\mC@arrow@linethickness,\mC@arrow@tikz] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height] at ($(\mC@arrow@name)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+     \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height] at ($(\mC@arrow@name)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@eqv% <->
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,mCtip-mCtip,\mC@arrow@linethickness] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+     \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@back% <-
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,mCtip-,\mC@arrow@linethickness] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+     \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@not% -|>
+     \let\mC@arrow@type@valid\mC@true%
+     \expandafter\draw\expandafter[\mC@arrow@tikz,-mCtip,\mC@arrow@linethickness] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+     \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!.8em!90:(@mC@arrow@end)$){#2};
+     \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!.8em!-90:(@mC@arrow@end)$){#3};
+     \draw ($(mC@arrow@center)!.6em!-110:(@mC@arrow@end)+(\mC@angle:.1em)$)--($(mC@arrow@center)!.6em!70:(@mC@arrow@end)+(\mC@angle:.1em)$);
+     \draw ($(mC@arrow@center)!.6em!-110:(@mC@arrow@end)+(180+\mC@angle:.1em)$)--($(mC@arrow@center)!.6em!70:(@mC@arrow@end)+(180+\mC@angle:.1em)$);
+   \fi
+   \ifx\mC@arrow@type@actual\mC@arrow@type@pm% -+>
+     \let\mC@arrow@type@valid\mC@true%
+     \def\mC@arrow@plusminus{true}
+     \draw[-mCtip,\mC@arrow@linethickness] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+   \fi
+   \ifx\mC@arrow@type@valid\mC@false%
+     \PackageError{myChemistry}{Unknown arrow type \mC@arrow@type@actual}{}
+   \fi
+ \else% default: ->
+   \expandafter\draw\expandafter[\mC@arrow@tikz,-mCtip,\mC@arrow@linethickness] let \n1={\mC@angle}, \n2={180+\mC@angle} in (@mC@arrow@start.\n1) --node[pos=.5,inner sep=0](\mC@arrow@name){} ++($(\mC@angle:\mC@arrow@factor*\mC@arrow@length)$);
+   \expandafter\node\expandafter[\mC@arrow@uplabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@up,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!\mC@arrow@label@dist!90:(@mC@arrow@end)$){#2};
+   \expandafter\node\expandafter[\mC@arrow@downlabel@visible,rotate=\mC@beta,anchor=\mC@arrow@label@anchor@down,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height,inner sep=0] at ($(\mC@arrow@name)!\mC@arrow@label@dist!-90:(@mC@arrow@end)$){#3};
+ \fi
+ \ifx\@empty\mC@arrow@plusminus\else
+   \ifx\@empty#2\@empty\else
+     \draw (\mC@arrow@name.base) edge[bend left] ++(${0.6667}*(146.3+\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$);
+     \node[anchor=\mC@arrow@label@anchor@add,inner sep=\mC@arrow@label@dist,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height] at ($(\mC@arrow@name.base)+{0.6667}*(146.3+\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$) {#2};
+   \fi
+   \ifx\@empty#3\@empty\else
+     \draw (\mC@arrow@name.base) edge[bend right,-mCtip] ++(${0.6667}*(33.7+\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$);
+     \node[anchor=\mC@arrow@label@anchor@sub,inner sep=\mC@arrow@label@dist,minimum width=\mC@arrow@label@width, minimum height=\mC@arrow@label@height] at ($(\mC@arrow@name.base)+{0.6667}*(33.7+\mC@angle:.5*\mC@arrow@factor*\mC@arrow@length)$) {#3};
+   \fi
+ \fi
+ \def\mC@arrow@factor{1}
+}
+
 % eigene Pfeilspitze ------------------------------------------------------------------ %
 \pgfarrowsdeclare{mCtip}{mCtip}%
 {
@@ -540,181 +616,37 @@
 \pgfpathlineto{\pgfpoint{0pt}{0pt}}
 \pgfusepathqfillstroke
 }
-% Pfeil zeichnen ---------------------------------------------------------------------- %
-\mC@def\mC@arrow@drawing{}
-\define@key{arrow}{type}[\mC@arrow@type]{%
-  \renewcommand{\mC@arrow@currenttype}{#1}
-  \ifthenelse{\equal{#1}{->}}{
-    \let\mC@arrow@plusminus\@empty
-    \renewcommand{\mC@arrow@drawing}{\draw[-mCtip,\mC@arrow@linethickness,text height=0] (0,0) -- node[pos=.5](@arrow@center){} ++(\mC@arrow@end);}
-  }{
-    \ifthenelse{\equal{#1}{<->}}{
-      \let\mC@arrow@plusminus\@empty
-      \renewcommand{\mC@arrow@drawing}{\draw[mCtip-mCtip,\mC@arrow@linethickness,text height=0] (0,0) -- node[pos=.5](@arrow@center){} ++(\mC@arrow@end);}
-    }{
-      \ifthenelse{\equal{#1}{<-}}{
-        \let\mC@arrow@plusminus\@empty
-        \renewcommand{\mC@arrow@drawing}{\draw[mCtip-,\mC@arrow@linethickness,text height=0] (0,0) -- node[pos=.5](@arrow@center){} ++(\mC@arrow@end);}
-      }{
-        \ifthenelse{\equal{#1}{<=>}}{
-          \let\mC@arrow@plusminus\@empty
-          \renewcommand{\mC@arrow@drawing}{\draw[-mChtip,\mC@arrow@linethickness,text height=0] (\mC@arrow@start@up) -- ++(\mC@arrow@end);\draw[mChtip-,\mC@arrow@linethickness,text height=0] (\mC@arrow@start@down) -- ++(\mC@arrow@end);\draw[draw=none] (0,0) -- node[pos=.5](@arrow@center){} ++(\mC@arrow@end);}
-        }{
-          \ifthenelse{\equal{#1}{-|>}}{
-            \let\mC@arrow@plusminus\@empty
-            \setlength{\mC@arrow@argument@aboveshift}{.75em}
-            \setlength{\mC@arrow@argument@belowshift}{.75em}
-            \renewcommand{\mC@arrow@cross@draw}{\draw[\mC@arrow@linethickness] ($(@arrow@center.base) + (\mC@arrow@cross@base@x,\mC@arrow@cross@base@y) + (\mC@arrow@cross@angle:\mC@arrow@cross@length)$) -- ($(@arrow@center.base) + (\mC@arrow@cross@base@x,\mC@arrow@cross@base@y) + (\mC@arrow@cross@angle-180:\mC@arrow@cross@length)$);\draw[\mC@arrow@linethickness] ($(@arrow@center.base) + (-\mC@arrow@cross@base@x,-\mC@arrow@cross@base@y) + (\mC@arrow@cross@angle:\mC@arrow@cross@length)$) -- ($(@arrow@center.base) + (-\mC@arrow@cross@base@x,-\mC@arrow@cross@base@y) + (\mC@arrow@cross@angle-180:\mC@arrow@cross@length)$);}
-            \renewcommand{\mC@arrow@drawing}{\draw[-mCtip,\mC@arrow@linethickness,text height=0] (0,0) -- node[pos=.5](@arrow@center){} ++(\mC@arrow@end);\mC@arrow@cross@draw}
-          }{
-            \ifthenelse{\equal{#1}{-+>}}{
-              \def\mC@arrow@plusminus{true}
-              \renewcommand{\mC@arrow@drawing}{\draw[-mCtip,\mC@arrow@linethickness,text height=0] (0,0) -- node[pos=.5](@arrow@center){} ++(\mC@arrow@end);}
-            }{
-              \PackageError{mychemistry}{Unknown arrow type}% oder Fehler
-            }
-          }
-        }
-      }
-    }
-  }
-}%
-% ------------------------------------------------------------------------------------- %
-% Maße der Nodes der Pfeilargumente bestimmen, größere später an Pfeil weitergeben
-\newlength{\mC@height@A}
-\newlength{\mC@height@B}
-\newlength{\mC@arrow@argument@height}
-\newlength{\mC@width@A}
-\newlength{\mC@width@B}
-\newlength{\mC@arrow@argument@width}
-\mC@def\mC@savenode{%
-    \global\let\mC@minx=\pgfpositionnodelaterminx%
-    \global\let\mC@maxx=\pgfpositionnodelatermaxx%
-    \global\let\mC@miny=\pgfpositionnodelaterminy%
-    \global\let\mC@maxy=\pgfpositionnodelatermaxy%
-}%
-% der nächste Befehl benötigt pgf v2.10!
-\mC@def\mC@largernode#1#2{
-  \@ifundefined{pgfpositionnodelater}{
-    \PackageError{mychemistry}{The command \string\pgfpositionnodelater is undefined. Make sure, you have installed the latest version of pgf.}
-  }{}
-  {\pgfpositionnodelater{\mC@savenode}
-  \node{#1};
-  \setlength{\mC@width@A}{\mC@maxx}%
-  \addtolength{\mC@width@A}{-\mC@minx}
-  \setlength{\mC@height@A}{\mC@maxy}%
-  \addtolength{\mC@height@A}{-\mC@miny}
-  \node{#2};
-  \setlength{\mC@width@B}{\mC@maxx}%
-  \addtolength{\mC@width@B}{-\mC@minx}
-  \setlength{\mC@height@B}{\mC@maxy}%
-  \addtolength{\mC@height@B}{-\mC@miny}
-  \pgfmathsetlength{\mC@arrow@argument@width}{max(\mC@width@A,\mC@width@B)}
-  \pgfmathsetlength{\mC@arrow@argument@height}{max(\mC@height@A,\mC@height@B)}
-  \global\mC@arrow@argument@width=\mC@arrow@argument@width
-  \global\mC@arrow@argument@height=\mC@arrow@argument@height
-  }
-}
-
-% Pfeil zeichnen ---------------------------------------------------------------------- %
-\mC@def\mC@arrow#1#2{
- \renewcommand{\mC@arrow@length@factor}{\mC@arrow@currentlength}
- \setlength{\mC@arrow@length@actual}{\mC@arrow@currentlength\mC@arrow@length@value}
- \ifthenelse{\equal{\mC@arrow@argument@both}{true}}{
-   \mC@largernode{#1}{#2}
- }{
-   \setlength{\mC@arrow@argument@width}{0pt}
-   \setlength{\mC@arrow@argument@height}{0pt}
- }
- \draw node[on chain=going \mC@arrow@currentdirection](\mC@arrow@currentname) {\tikz{
-   \mC@arrow@drawing
-   }
- };
- \mC@arrow@argument@anchor
- \ifx\@empty\mC@arrow@plusminus
-   \draw node[anchor=\mC@arrow@above@anchor,rotate=\mC@arrow@rotate,minimum width=\mC@arrow@argument@width, minimum height=\mC@arrow@argument@height]
-    at ($(@arrow@center.base)+(90+\mC@arrow@argument@angle:\mC@arrow@argument@aboveshift)$) {#1};
-   \draw node[anchor=\mC@arrow@below@anchor,rotate=\mC@arrow@rotate,minimum width=\mC@arrow@argument@width, minimum height=\mC@arrow@argument@height]
-    at ($(@arrow@center.base)+(-90+\mC@arrow@argument@angle:\mC@arrow@argument@belowshift)$) {#2};
- \else
-   \draw (@arrow@center.base) edge[bend left] ++(146.3+\mC@arrow@argument@angle:.361\mC@arrow@length@actual);
-   \node[anchor=\mC@arrow@above@anchor,inner sep=.1em] at ($(@arrow@center.base)+(146.3+\mC@arrow@argument@angle:.361\mC@arrow@length@actual)$) {#1};
-   \draw (@arrow@center.base) edge[bend right,-mCtip] ++(33.7+\mC@arrow@argument@angle:.361\mC@arrow@length@actual);
-   \node[anchor=\mC@arrow@above@anchor,inner sep=.1em] at ($(@arrow@center.base)+(33.7+\mC@arrow@argument@angle:.361\mC@arrow@length@actual)$) {#2};
- \fi
- \setlength{\mC@arrow@argument@aboveshift}{2pt}
- \setlength{\mC@arrow@argument@belowshift}{2pt}
-}
-
-% Voreinstellungen:
-\presetkeys%
-  {arrow}
-  {direction=\mC@arrow@direction,length=\mC@arrow@length,type=\mC@arrow@type,aboveshift=\mC@arrow@argument@shift,belowshift=\mC@arrow@argument@shift}
-  {}
-
-% Eigentlicher Befehl:
-\mC@def\arrow{\@ifnextchar[{\mC@arrow@i}{\setkeys{arrow}{}\mC@arrow}}
-\mC@def\mC@arrow@i[#1]{% [<direction>,<type>,<length>,<name>,both]
-  \let\mC@remainargs\@empty\mC@splitarg{#1}%
-  \ifx\@empty\mC@firstarg% erste Option: direction
-    \def\mC@arrow@key@direction{right}%
-  \else%
-    \let\mC@arrow@key@direction\mC@firstarg%
-  \fi%
-  \ifx\@empty\mC@secondarg% zweite Option: type
-    \def\mC@arrow@key@type{->}%
-  \else%
-    \let\mC@arrow@key@type\mC@secondarg%
-  \fi%
-  \let\mC@remainargs\@empty%
-  \expandafter\mC@splitarg\expandafter{\mC@thirdarg}%
-  \ifx\@empty\mC@firstarg% dritte Option: length
-    \def\mC@arrow@key@length{1.0}%
-  \else%
-    \let\mC@arrow@key@length\mC@firstarg%
-  \fi%
-  \ifx\@empty\mC@secondarg% vierte Option: name
-    \let\mC@arrow@key@name\@empty%
-  \else%
-    \def\mC@arrow@key@name{\mC@secondarg}%
-  \fi%
-  \ifx\@empty\mC@thirdarg% fünfte Option: both
-      \let\mC@arrow@key@both\@empty%
-    \else%
-    \let\mC@arrow@key@both\mC@thirdarg%
-  \fi%
-  \setkeys{arrow}{direction=\mC@arrow@key@direction,type={\mC@arrow@key@type},length={\mC@arrow@key@length},name=\mC@arrow@key@name,\mC@arrow@key@both}\mC@arrow%
-}
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % MERGE ------------------------------------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mC@def\mC@merge@length@default{3em}
-\mC@def\mC@merge@length@value{\mC@merge@length@default}
+% \merge[<label>,<pos>,<length>]{<target>}{<start a>}{<start b>}
+\def\mC@merge@length@default{3em}
+\def\mC@merge@length@value{\mC@merge@length@default}
 % Basisbefehle ------------------------------------------------------------------------ %
-\mC@def\mC@merge@right{
+\def\mC@merge@right{
  \draw[mCtip-,\mC@arrow@linethickness] ($(\mC@merge@to.west)+(-\mC@rxn@node@distance,0)$) --node[midway,above,yshift=.1em]{\mC@merge@arg} ++(-\mC@merge@length,0) node(crossing) {};
- \draw[thick] ($(\mC@merge@from@one.east)+(\mC@rxn@node@distance,0)$) -| (crossing.base);
- \draw[thick] ($(\mC@merge@from@two.east)+(\mC@rxn@node@distance,0)$) -| (crossing.base);
+ \draw[\mC@arrow@linethickness] ($(\mC@merge@from@one.east)+(\mC@rxn@node@distance,0)$) -| (crossing.base);
+ \draw[\mC@arrow@linethickness] ($(\mC@merge@from@two.east)+(\mC@rxn@node@distance,0)$) -| (crossing.base);
 }
-\mC@def\mC@merge@above{
+\def\mC@merge@above{
  \draw[mCtip-,\mC@arrow@linethickness] ($(\mC@merge@to.south)+(0,-\mC@rxn@node@distance)$) --node[midway,right,xshift=.1em]{\mC@merge@arg} ++(0,-\mC@merge@length) node(crossing) {};
- \draw[thick] (crossing.base) -| ($(\mC@merge@from@one.north)+(0,\mC@rxn@node@distance)$);
- \draw[thick] (crossing.base) -| ($(\mC@merge@from@two.north)+(0,\mC@rxn@node@distance)$);
+ \draw[\mC@arrow@linethickness] (crossing.base) -| ($(\mC@merge@from@one.north)+(0,\mC@rxn@node@distance)$);
+ \draw[\mC@arrow@linethickness] (crossing.base) -| ($(\mC@merge@from@two.north)+(0,\mC@rxn@node@distance)$);
 }
-\mC@def\mC@merge@left{
+\def\mC@merge@left{
  \draw[mCtip-,\mC@arrow@linethickness] ($(\mC@merge@to.east)+(\mC@rxn@node@distance,0)$) --node[midway,above,yshift=.1em]{\mC@merge@arg} ++(\mC@merge@length,0) node(crossing) {};
- \draw[thick] ($(\mC@merge@from@one.west)+(-\mC@rxn@node@distance,0)$) -| (crossing.base);
- \draw[thick] ($(\mC@merge@from@two.west)+(-\mC@rxn@node@distance,0)$) -| (crossing.base);
+ \draw[\mC@arrow@linethickness] ($(\mC@merge@from@one.west)+(-\mC@rxn@node@distance,0)$) -| (crossing.base);
+ \draw[\mC@arrow@linethickness] ($(\mC@merge@from@two.west)+(-\mC@rxn@node@distance,0)$) -| (crossing.base);
 }
-\mC@def\mC@merge@below{
+\def\mC@merge@below{
  \draw[mCtip-,\mC@arrow@linethickness] ($(\mC@merge@to.north)+(0,\mC@rxn@node@distance)$) --node[midway,right,xshift=.1em]{\mC@merge@arg} ++(0,\mC@merge@length) node(crossing) {};
- \draw[thick] (crossing.base) -| ($(\mC@merge@from@one.south)+(0,-\mC@rxn@node@distance)$);
- \draw[thick] (crossing.base) -| ($(\mC@merge@from@two.south)+(0,-\mC@rxn@node@distance)$);
+ \draw[\mC@arrow@linethickness] (crossing.base) -| ($(\mC@merge@from@one.south)+(0,-\mC@rxn@node@distance)$);
+ \draw[\mC@arrow@linethickness] (crossing.base) -| ($(\mC@merge@from@two.south)+(0,-\mC@rxn@node@distance)$);
 }
 % eigentlicher Befehl ----------------------------------------------------------------- %
-\mC@def\mC@merge{\@ifnextchar[{\mC@merge@ii}{\mC@merge@i}}
-\mC@def\mC@merge@i#1#2#3{
+\def\mC@merge{\@ifnextchar[{\mC@merge@ii}{\mC@merge@i}}
+\def\mC@merge@i#1#2#3{
   \def\mC@merge@length{\mC@merge@length@value}
   \let\mC@merge@arg\@empty
   \def\mC@merge@to{#1}
@@ -722,7 +654,7 @@
   \def\mC@merge@from@two{#3}
   \mC@merge@below
 }
-\mC@def\mC@merge@ii[#1]#2#3#4{
+\def\mC@merge@ii[#1]#2#3#4{
   \let\mC@remainargs\@empty\mC@splitarg{#1}
   \ifx\mC@firstarg\@empty
     \let\mC@merge@arg\@empty
@@ -743,9 +675,9 @@
     \expandafter\csname mC@merge@\mC@secondarg\endcsname
   \fi
 }
-\mC@def\merge{\mC@merge}
+\def\merge{\mC@merge}
 
-\mC@def\setmergelength#1{
+\def\setmergelength#1{
   \ifx\@empty#1\@empty
     \def\mC@merge@length@value{\mC@merge@length@default}
   \else
@@ -760,7 +692,7 @@
 \setlength{\mC@rxn@node@distance@default}{1em}
 \newlength{\mC@rxn@node@distance}
 \setlength{\mC@rxn@node@distance}{\mC@rxn@node@distance@default}
-\mC@def\setrcndist#1{%
+\def\setrcndist#1{%
   \ifx\@empty#1\@empty%
     \setlength{\mC@rxn@node@distance}{\mC@rxn@node@distance@default}%
   \else%
@@ -770,17 +702,18 @@
 % ------------------------------------------------------------------------------------- %
 % Schema ------------------------------------------------------------------------------ %
 % ------------------------------------------------------------------------------------- %
-\mC@def\mC@rs@scale{1.0}                         % Default-Skalierung
-\mC@def\mC@rs@currentscale{\mC@rs@scale}         %
-\mC@def\setschemename#1{\def\mC@rs@name{#1}}     %
-\mC@def\mC@rs@caption{}                          % Beschriftung
-\mC@def\mC@rs@label{}                            % Label
-\mC@def\mC@rs@currentlabel{\mC@rs@label}         %
-\mC@def\mC@rs@align{center}                      %
-\mC@def\mC@rs@right{right}                       %
-\mC@def\mC@rs@center{center}                     %
-\mC@def\mC@rs@left{left}                         %
-\mC@def\setschemealign#1{%                       %
+% \begin{rxnscheme}[<label>,<placement>,<align>,<scale factor>,<name>]{<caption>}
+\def\mC@rs@scale{1.0}                            % Default-Skalierung
+\def\mC@rs@currentscale{\mC@rs@scale}            %
+\def\setschemename#1{\def\mC@rs@name{#1}}        %
+\def\mC@rs@caption{}                             % Beschriftung
+\def\mC@rs@label{}                               % Label
+\def\mC@rs@currentlabel{\mC@rs@label}            %
+\def\mC@rs@align{center}                         %
+\def\mC@rs@right{right}                          %
+\def\mC@rs@center{center}                        %
+\def\mC@rs@left{left}                            %
+\def\setschemealign#1{%                          %
   \ifx\@empty#1\@empty%                          %
     \def\mC@rs@align{center}%                    %
   \else%                                         %
@@ -792,8 +725,8 @@
 \newfloat{rxnfloat}{\mC@rs@currentplacement}{rxnscheme}
 \floatname{rxnfloat}{\mC@rs@name}                % Name ändern
 % eigentliche Umgebung:
-\mC@def\mC@rxnscheme{\@ifnextchar[{\mC@rxnscheme@ii}{\let\mC@rs@currentlabel\@empty\mC@rxnscheme@i}}
-\mC@def\mC@rxnscheme@ii[#1]{% [<label>,<placement>,<align>,<scale>,<name>]
+\def\mC@rxnscheme{\@ifnextchar[{\mC@rxnscheme@ii}{\let\mC@rs@currentlabel\@empty\mC@rxnscheme@i}}
+\def\mC@rxnscheme@ii[#1]{% [<label>,<placement>,<align>,<scale>,<name>]
   \let\mC@remainargs\@empty\mC@splitarg{#1}%
   \ifx\@empty\mC@firstarg% erste Option
     \let\mC@rs@currentlabel\@empty%
@@ -822,7 +755,7 @@
   \fi%
   \mC@rxnscheme@i%
 }
-\mC@def\mC@rxnscheme@i#1{%
+\def\mC@rxnscheme@i#1{%
   \def\mC@rs@caption{#1}%
   \rxnfloat%
   \ifx\mC@rs@align\mC@rs@center \centering \fi%
@@ -832,8 +765,8 @@
   \tikzpicture[every picture/.style={scale=\mC@rs@currentscale},start chain,node distance=\mC@rxn@node@distance,inner sep=0pt,outer sep=0pt]%
   \mC@dummy@ii%
 }
-\mC@def\rxnscheme{\mC@rxnscheme}
-\mC@def\endrxnscheme{%
+\def\rxnscheme{\mC@rxnscheme}
+\def\endrxnscheme{%
   \endtikzpicture%
   \caption{\mC@rs@caption}%
   \ifx\@empty\mC@rs@currentlabel\else%
@@ -845,21 +778,22 @@
 % ------------------------------------------------------------------------------------- %
 % einfache Reaktion ------------------------------------------------------------------- %
 % ------------------------------------------------------------------------------------- %
-\mC@def\mC@reaction@scale{1.0}
-\mC@def\mC@reaction@align{center}
-\mC@def\setrxnalign#1{
+% \begin{rxn}[<align>,<scalefactor>]
+\def\mC@reaction@scale{1.0}
+\def\mC@reaction@align{center}
+\def\setrxnalign#1{
   \ifx\@empty#1\@empty
     \def\mC@reaction@align{center}
   \else
     \def\mC@reaction@align{#1}
   \fi
 }
-\mC@def\mC@reaction@right{right}
-\mC@def\mC@reaction@center{center}
-\mC@def\mC@reaction@left{left}
+\def\mC@reaction@right{right}
+\def\mC@reaction@center{center}
+\def\mC@reaction@left{left}
 
-\mC@def\mC@rxn{\@ifnextchar[{\mC@rxn@ii}{\mC@rxn@i}}
-\mC@def\mC@rxn@ii[#1]{%
+\def\mC@rxn{\@ifnextchar[{\mC@rxn@ii}{\mC@rxn@i}}
+\def\mC@rxn@ii[#1]{%
   \let\mC@remainargs\@empty\mC@splitarg{#1}%
   \ifx\@empty\mC@firstarg%
     \let\mC@reaction@align\mC@reaction@center%
@@ -873,7 +807,7 @@
   \fi%
   \mC@rxn@i
 }
-\mC@def\mC@rxn@i{%
+\def\mC@rxn@i{%
   \hspace*{0pt}%
   \ifx\mC@reaction@align\mC@reaction@center%
     \center%
@@ -885,12 +819,12 @@
     \flushright%
   \fi%
   \mC@bondlength\mC@bondshape\mC@atomsize%
-  \tikzpicture[every picture/.style={scale=\mC@reaction@scale},start chain,node distance=\mC@rxn@node@distance,inner sep=0pt,outer sep=0pt]%
+  \begin{tikzpicture}[every picture/.style={scale=\mC@reaction@scale},start chain,node distance=\mC@rxn@node@distance,inner sep=0pt,outer sep=0pt]%
   \mC@dummy@ii%
 }
-\mC@def\rxn{\mC@rxn}
-\mC@def\endrxn{%
-  \endtikzpicture%
+\def\rxn{\mC@rxn}
+\def\endrxn{%
+  \end{tikzpicture}%
   \ifx\mC@reaction@align\mC@reaction@center%
     \endcenter%
   \fi%
@@ -906,89 +840,174 @@
 % REAKTANDEN -------------------------------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Standardreaktand -------------------------------------------------------------------- %
-\mC@def\mC@reactant{\@ifnextchar[{\mC@reactant@ii}{\mC@reactant@i}}
-\mC@def\mC@reactant@i#1{\def\mC@firstarg{on chain=going right}\let\mC@secondarg\@empty\let\mC@thirdarg\@empty\mC@reactant@iii{#1}}
-\mC@def\mC@reactant@ii[#1]#2{
+% \reactant[<pos>,<name>,<tikz>]{<something>}
+\def\reactant{\@ifnextchar[{\reactant@ii}{\reactant@i}}
+\def\reactant@i#1{
+  \expandafter\node\expandafter[\mC@reactant@visible,on chain=going {at=(\tikzchainprevious.0)},anchor=180,shift=(0:\mC@rxn@node@distance)]{\scantokens{\relax#1}};
+}
+\def\reactant@ii[#1]#2{
   \let\mC@remainargs\@empty\mC@splitarg{#1}
-  \ifx\mC@firstarg\@empty\def\mC@reactant@alignment{right}\else\let\mC@reactant@alignment\mC@firstarg\fi
-  \def\mC@firstarg{on chain=going \mC@reactant@alignment}
-  \mC@reactant@iii{#2}}
-\mC@def\mC@reactant@iii#1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg](\mC@secondarg){\scantokens{\relax#1}};}% scantokens nötig, da sonst eine Dreifanchbindung ~ vor () mit falschem catcode interpretiert wird
-\mC@def\reactand{\mC@reactant}% old command
-\mC@def\reactant{\mC@reactant}% new correctly spelled command
+  \ifx\@empty\mC@firstarg% erste Option: <pos>, zweite Option: <name>, dritte Option: <tikz>
+    \def\mC@angle{0}
+    \def\mC@anchor{180}
+    \let\mC@referred@node\@empty
+  \else
+    \expandafter\mC@analyze@angle\expandafter{\mC@firstarg}
+    \def\mC@anchor{180+\mC@angle}
+  \fi
+  \ifx\mC@referred@node\@empty\def\mC@referred@node{\tikzchainprevious}\fi
+  \expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@thirdarg\expandafter,\mC@reactant@visible,on chain=going {at=(\mC@referred@node.\mC@angle)},anchor=\mC@anchor,shift=(\mC@angle:\mC@rxn@node@distance)](\mC@secondarg){\scantokens{\relax#2}};
+}
+\let\reactand\reactant
 
 % Mesomerie --------------------------------------------------------------------------- %
-\mC@def\mC@mesomeric{\@ifnextchar[{\mC@mesomeric@ii}{\mC@mesomeric@i}}
-\mC@def\mC@mesomeric@i#1{\def\mC@firstarg{on chain=going right}\let\mC@secondarg\@empty\let\mC@thirdarg\@empty\mC@mesomeric@iii{#1}}
-\mC@def\mC@mesomeric@ii[#1]#2{
+% \mesomeric[<pos>,<name>,<tikz>]{<something>}
+\def\mesomeric{\@ifnextchar[{\mesomeric@ii}{\mesomeric@i}}
+\def\mesomeric@i#1{
+  \node[on chain=going {at=(\tikzchainprevious.0),shift=($(0:\mC@rxn@node@distance)$)},anchor=180,shift=(0:\mC@rxn@node@distance),inner sep=1pt,left delimiter={[},right delimiter={]}]{\tikzpicture[start branch]\scantokens{\relax#1}\endtikzpicture};
+}
+\def\mesomeric@ii[#1]#2{
   \let\mC@remainargs\@empty\mC@splitarg{#1}
-  \ifx\mC@firstarg\@empty\def\mC@mesomeric@alignment{right}\else\let\mC@mesomeric@alignment\mC@firstarg\fi
-  \def\mC@firstarg{on chain=going \mC@mesomeric@alignment}
-  \mC@mesomeric@iii{#2}}
-\mC@def\mC@mesomeric@iii#1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg,inner sep=1pt,left delimiter={[},right delimiter={]}](\mC@secondarg){\tikzpicture[start branch]\scantokens{\relax#1}\endtikzpicture};}% scantokens nötig, da sonst eine Dreifanchbindung ~ vor () mit falschem catcode interpretiert wird
-\mC@def\mesomeric{\mC@mesomeric}
+  \ifx\@empty\mC@firstarg% erste Option: <pos>, zweite Option: <name>, dritte Option: <tikz>
+    \def\mC@angle{0}
+    \def\mC@anchor{180}
+    \let\mC@referred@node\@empty
+  \else
+    \expandafter\mC@analyze@angle\expandafter{\mC@firstarg}
+    \def\mC@anchor{180+\mC@angle}
+  \fi
+  \ifx\mC@referred@node\@empty\def\mC@referred@node{\tikzchainprevious}\fi
+  \expandafter\node\expandafter[\mC@thirdarg,on chain=going {at=(\mC@referred@node.\mC@angle)},anchor=\mC@anchor,shift=(\mC@angle:\mC@rxn@node@distance),inner sep=1pt,left delimiter={[},right delimiter={]}](\mC@secondarg){\tikzpicture[start branch]\scantokens{\relax#2}\endtikzpicture};
+}
 
 % Mesomerie-Pfeil --------------------------------------------------------------------- %
-\mC@def\marrow{\@ifnextchar[{\mC@marrow@i}{\mC@marrow@ii}}
-\mC@def\mC@marrow@i[#1]{\arrow[#1,<->,.5]{}{}}
-\mC@def\mC@marrow@ii{\arrow[,<->,.5]{}{}}
+% \marrow[<pos>]
+\def\marrow{\@ifnextchar[{\mC@marrow@ii}{\mC@marrow@i}}
+\def\mC@marrow@ii[#1]{\arrow[#1,<->,.5]{}{}}
+\def\mC@marrow@i{\arrow[,<->,.5]{}{}}
 
 % Anywhere ---------------------------------------------------------------------------- %
-\mC@def\mC@anywhere{\@ifnextchar[{\mC@anywhere@ii}{\mC@anywhere@i}}
-\mC@def\mC@anywhere@ii[#1]#2#3{\node[#2](#1){#3};}
-\mC@def\mC@anywhere@i#1#2{\node[#1]{#2};}
-\mC@def\anywhere{\mC@anywhere}
+% \anywhere{<pos>,<name>,<tikz>}{<something>}
+\def\anywhere#1#2{
+  \let\mC@remainargs\@empty\mC@splitarg{#1}% erste Option: <pos>, zweite Option: <name>, dritte Option: <tikz>
+  \ifx\mC@firstarg\@empty
+    \PackageError{mychemistry}{\string\anywhere: positioning missing}{See the myChemistry package documentation for explanation}
+  \else
+    \expandafter\mC@if@instr\expandafter{\mC@firstarg}{=}{
+      \edef\mC@anywhere@positioning{\mC@firstarg}
+    }{
+      \expandafter\mC@analyze@angle\expandafter{\mC@firstarg}
+      \def\mC@anchor{180+\mC@angle}
+      \ifx\mC@referred@node\@empty
+        \PackageError{mychemistry}{You can't use `angle' to position \string\anywhere. You need to use `name.angle'}{See the myChemistry package documentation for explanation}
+      \else
+        \def\mC@anywhere@positioning{at=(\mC@referred@node.\mC@angle),anchor=\mC@anchor}
+      \fi
+    }
+  \fi
+  \expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@thirdarg\expandafter,\mC@anywhere@positioning](\mC@secondarg){#2};
+}
 
 % Dummy ------------------------------------------------------------------------------- %
-\mC@def\dummy{\@ifnextchar[{\mC@dummy@i}{\mC@dummy@ii}}
-\mC@def\mC@dummy@i[#1]{\draw node[on chain,xshift=-\mC@rxn@node@distance](#1){};}
-\mC@def\mC@dummy@ii{\draw node[on chain,xshift=-\mC@rxn@node@distance]{};}
+% \dummy[<name>]
+\def\dummy{\@ifnextchar[{\mC@dummy@i}{\mC@dummy@ii}}
+\def\mC@dummy@i[#1]{\draw node[on chain,xshift=-\mC@rxn@node@distance](#1){};}
+\def\mC@dummy@ii{\draw node[on chain,xshift=-\mC@rxn@node@distance]{};}
 
 % Uebergangszustand ------------------------------------------------------------------- %
-\mC@def\mC@transition@name{x}
-\mC@def\mC@transition{\@ifnextchar[{\mC@transition@ii}{\mC@transition@i}}
-\mC@def\mC@transition@i#1{\def\mC@firstarg{on chain=going right}\let\mC@secondarg\mC@transition@name\let\mC@thirdarg\@empty\mC@transition@iii{#1}}
-\mC@def\mC@transition@ii[#1]#2{
+% \transition[<pos>,<name>,<tikz>]{<something>}
+\def\transition{\@ifnextchar[{\transition@ii}{\transition@i}}
+\def\transition@i#1{
+  \expandafter\node\expandafter[\mC@reactant@visible,on chain=going {at=(\tikzchainprevious.0)},anchor=180,shift=(0:\mC@rxn@node@distance),anchor=180,inner sep=3pt,left delimiter={[},right delimiter={]}](mC@transition@name){\scantokens{\relax#1}};
+  \node at ($(mC@transition@name.north east)+(.7em,0)$) {$\ddagger$};
+}
+\def\transition@ii[#1]#2{
   \let\mC@remainargs\@empty\mC@splitarg{#1}
-  \ifx\mC@firstarg\@empty\def\mC@transition@alignment{right}\else\let\mC@transition@alignment\mC@firstarg\fi
-  \def\mC@firstarg{on chain=going \mC@transition@alignment}
-  \ifx\mC@secondarg\@empty\let\mC@secondarg\mC@transition@name\fi
-  \mC@transition@iii{#2}}
-\mC@def\mC@transition@iii#1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg,inner sep=1pt,left delimiter={[},right delimiter={]}](\mC@secondarg){\scantokens{\relax#1}} node[above right=of \mC@secondarg,xshift=-.2em,yshift=-1.2em] {$\ddagger$};}% scantokens nötig, da sonst eine Dreifanchbindung ~ vor () mit falschem catcode interpretiert wird
-\mC@def\transition{\mC@transition}
+  \ifx\@empty\mC@firstarg% erste Option: <pos>
+    \def\mC@angle{0}
+    \def\mC@anchor{180}
+    \let\mC@referred@node\@empty
+  \else
+    \expandafter\mC@analyze@angle\expandafter{\mC@firstarg}
+    \def\mC@anchor{180+\mC@angle}
+  \fi
+  \ifx\@empty\mC@secondarg% zweite Option: <name>, dritte Option: <tikz>
+    \def\mC@transition@name{mC@transition@name}
+  \else
+    \let\mC@transition@name\mC@secondarg
+  \fi
+  \ifx\mC@referred@node\@empty\def\mC@referred@node{\tikzchainprevious}\fi
+  \expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\mC@reactant@visible\expandafter,\mC@thirdarg,on chain=going {at=(\mC@referred@node.\mC@angle)},anchor=\mC@anchor,shift=(\mC@angle:\mC@rxn@node@distance),inner sep=3pt,left delimiter={[},right delimiter={]}](\mC@transition@name){\scantokens{\relax#2}};
+  \node at ($(\mC@transition@name.north east)+(.7em,0)$) {$\ddagger$};
+}
 
 % Abzweigung -------------------------------------------------------------------------- %
-\mC@def\mC@branch{\@ifnextchar[{\mC@branch@ii}{\mC@branch@i}}
-\mC@def\mC@branch@i#1{\def\mC@firstarg{on chain=going right}\let\mC@secondarg\@empty\let\mC@thirdarg\@empty\mC@branch@iii{#1}}
-\mC@def\mC@branch@ii[#1]#2{\let\mC@remainargs\@empty\mC@splitarg{#1}\ifx\mC@firstarg\@empty\def\mC@firstarg{on chain=going right}\fi\mC@branch@iii{#2}}
-\mC@def\mC@branch@iii#1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg](\mC@secondarg){\tikzpicture[start branch]\scantokens{\relax#1}\endtikzpicture};}% scantokens nötig, da sonst eine Dreifanchbindung ~ vor () mit falschem catcode interpretiert wird
-\mC@def\branch{\mC@branch}
+% \branch[<pos>,<name>,<tikz>]{<formulae>}
+% <pos>: default: on chain=going "right" (0°)
+%        on chain=going <somewhere>
+%        <somewhere>=of <name>
+%        <angle> (sitzt auf der Kette)
+%        <name>.<angle> (sitzt nicht auf der Kette)
+\def\mC@branch{\@ifnextchar[{\mC@branch@ii}{\mC@branch@i}}
+\def\mC@branch@i#1{
+  \expandafter\def\expandafter\mC@branch@positioning\expandafter{\mC@branch@visible,on chain=going {at=(\tikzchainprevious.0)},anchor=180,shift=(0:\mC@rxn@node@distance)}
+  \let\mC@secondarg\@empty\let\mC@thirdarg\@empty
+  \mC@branch@iii{#1}}
+\def\mC@branch@ii[#1]#2{
+  \let\mC@remainargs\@empty\mC@splitarg{#1}% erste Option: <pos>, zweite Option: <name>, dritte Option: <tikz>
+  \ifx\mC@firstarg\@empty
+    \expandafter\def\expandafter\mC@branch@positioning\expandafter{\mC@branch@visible,on chain=going {at=(\tikzchainprevious.0)},anchor=180,shift=(0:\mC@rxn@node@distance)}
+  \else
+    \expandafter\mC@if@instr\expandafter{\mC@firstarg}{=}{
+      \edef\mC@branch@positioning{\mC@branch@visible,\mC@firstarg}
+    }{
+      \expandafter\mC@analyze@angle\expandafter{\mC@firstarg}
+      \def\mC@anchor{180+\mC@angle}
+      \ifx\mC@referred@node\@empty
+        \expandafter\def\expandafter\mC@branch@positioning\expandafter{\mC@branch@visible,on chain=going {at=(\tikzchainprevious.\mC@angle)},anchor=\mC@anchor,shift=(\mC@angle:\mC@rxn@node@distance)}
+      \else
+        \expandafter\def\expandafter\mC@branch@positioning\expandafter{\mC@branch@visible,at=(\mC@referred@node.\mC@angle),anchor=\mC@anchor,shift=(\mC@angle:\mC@rxn@node@distance)}
+      \fi
+    }
+  \fi
+  \mC@branch@iii{#2}}
+\def\mC@branch@iii#1{
+  \expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@branch@positioning\expandafter,\mC@thirdarg](\mC@secondarg){\tikzpicture[start branch]\scantokens{\relax#1}\endtikzpicture};}% scantokens nötig, da sonst eine Dreifachbindung ~ vor () mit falschem catcode interpretiert wird
+\def\branch{\mC@branch}
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Sonstiges --------------------------------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Elektronenverschiebungspfeile ------------------------------------------------------- %
-\mC@def\elmove{\@ifnextchar[{\mC@elmove@i}{\mC@elmove@ii}}
-\mC@def\mC@elmove@i[#1]#2#3#4#5{\chemmove{\draw[#1](#2).. controls +(#3) and +(#5)..(#4);}}
-\mC@def\mC@elmove@ii#1#2#3#4{\chemmove{\draw[->,red,shorten <=3pt,shorten >=1pt](#1).. controls +(#2) and +(#4)..(#3);}}
+\def\elmove{\@ifnextchar[{\mC@elmove@i}{\mC@elmove@ii}}
+\def\mC@elmove@i[#1]#2#3#4#5{\chemmove{\draw[#1](#2).. controls +(#3) and +(#5)..(#4);}}
+\def\mC@elmove@ii#1#2#3#4{\chemmove{\draw[->,red,shorten <=3pt,shorten >=1pt](#1).. controls +(#2) and +(#4)..(#3);}}
+
+% Plus -------------------------------------------------------------------------------- %
+\def\mC@chemand{\@ifnextchar[{\mC@chemand@ii}{\mC@chemand@i}}
+\def\mC@chemand@i{\reactant{\chemsign[0pt]{+}}}
+\def\mC@chemand@ii[#1]{\reactant[#1]{\chemsign[0pt]{+}}}
+\def\chemand{\mC@chemand}
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Setup myChemistry ------------------------------------------------------------------- %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Bindungslänge ----------------------------------------------------------------------- %
-\mC@def\mC@bondlength@default{1.8em}
-\mC@def\mC@bondlength{\setatomsep{\mC@bondlength@default}}
-\mC@def\setbondlength#1{
+\def\mC@bondlength@default{1.8em}
+\def\mC@bondlength{\setatomsep{\mC@bondlength@default}}
+\def\setbondlength#1{
  \ifx\@empty#1\@empty
   \def\mC@bondlength{\setatomsep{\mC@bondlength@default}}
  \else
   \def\mC@bondlength{\setatomsep{#1}}
  \fi
 }
-% \let\bondlength\setbondlength
 
 % Keilbindungen ----------------------------------------------------------------------- %
-\mC@def\mC@bondshape@one{3pt}
-\mC@def\mC@bondshape@two{.5pt}
-\mC@def\mC@bondshape@three{1pt}
-\mC@def\setbondshape#1#2#3{
+\def\mC@bondshape@one{3pt}
+\def\mC@bondshape@two{.5pt}
+\def\mC@bondshape@three{1pt}
+\def\setbondshape#1#2#3{
  \ifx\@empty#1\@empty
   \renewcommand{\mC@bondshape@one}{3pt}
  \else
@@ -1005,37 +1024,24 @@
   \renewcommand{\mC@bondshape@three}{#3}
  \fi
 }
-% \let\bondshape\setbondshape
-\mC@def\mC@bondshape{\setcrambond{\mC@bondshape@one}{\mC@bondshape@two}{\mC@bondshape@three}}
+\def\mC@bondshape{\setcrambond{\mC@bondshape@one}{\mC@bondshape@two}{\mC@bondshape@three}}
 
 % Atomgröße --------------------------------------------------------------------------- %
-\mC@def\mC@atomsize@default{\small}
-\mC@def\mC@atomsize{\mC@atomsize@default}
-\mC@def\setatomsize#1{
+\def\mC@atomsize@default{\small}
+\def\mC@atomsize{\mC@atomsize@default}
+\def\setatomsize#1{
  \ifx\@empty#1\@empty
   \renewcommand{\mC@atomsize}{\mC@atomsize@default}
  \else
   \renewcommand{\mC@atomsize}{#1}
  \fi
 }
-% \let\atomsize\setatomsize
 
-% Plus -------------------------------------------------------------------------------- %
-\mC@def\mC@chemand{\@ifnextchar[{\mC@chemand@ii}{\mC@chemand@i}}
-\mC@def\mC@chemand@i{\def\mC@firstarg{on chain=going right}\let\mC@secondarg\@empty\let\mC@thirdarg\@empty\mC@chemand@iii}
-\mC@def\mC@chemand@ii[#1]{
-  \let\mC@remainargs\@empty\mC@splitarg{#1}
-  \ifx\mC@firstarg\@empty\def\mC@chemand@alignment{right}\else\let\mC@chemand@alignment\mC@firstarg\fi
-  \def\mC@firstarg{on chain=going \mC@chemand@alignment}
-  \mC@chemand@iii}
-\mC@def\mC@chemand@iii{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg](\mC@secondarg){\chemsign[0pt]{+}};}
-\mC@def\chemand{\mC@chemand}
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-% Setup myChemistry ------------------------------------------------------------------- %
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\mC@def\mCsetup#1{\setkeys{setup}{#1}}
-\define@key{setup}{arrowlength}[\mC@arrow@length@default]{%
+% allg. Setup ------------------------------------------------------------------------- %
+\def\mCsetup#1{\setkeys{setup}{#1}}
+\define@key{setup}{arrowlabel}[\mC@arrow@label@dist@def]{%
+  \setarrowlabel{#1}}
+\define@key{setup}{arrowlength}[\mC@arrow@length@def]{%
   \setarrowlength{#1}}
 \define@key{setup}{arrowline}[\mC@arrow@linethickness@default]{%
   \setarrowline{#1}}
@@ -1043,6 +1049,9 @@
   \setatomsize{#1}}
 \define@key{setup}{bondlength}[\mC@bondlength@default]{%
   \setbondlength{#1}}
+% \define@key{setup}{bondshape}[{\mC@bondshape@one,\mC@bondshape@two\mC@bondshape@three}]{%
+%   \let\mC@remainargs\@empty\mC@splitarg{#1}%
+%   \setbondshape{\mC@firstarg}{\mC@secondarg}{\mC@thirdarg}}
 \define@key{setup}{rcndist}[\mC@rxn@node@distance@default]{%
   \setrcndist{#1}}
 \define@key{setup}{rxnalign}[center]{%
@@ -1055,6 +1064,7 @@
 \define@key{setup}{mergelength}[\mC@merge@length@default]{
   \setmergelength{#1}}
 \define@key{setup}{reset}[]{%
+  \setarrowlabel{}
   \setarrowlength{}
   \setarrowline{}
   \setmergelength{}
@@ -1069,58 +1079,21 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % NODES SICHTBAR/UNSICHTBAR MACHEN ---------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\newcommand\makevisible{
-  \def\mC@reactant@iii##1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg,draw=red!60,solid](\mC@secondarg){\scantokens{\relax##1}};}
-  \def\mC@branch@iii##1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg,draw=purple,dotted](\mC@secondarg){\tikzpicture[start branch]\scantokens{\relax##1}\endtikzpicture};}
-  \def\mC@transition@iii##1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg,inner sep=1pt,left delimiter={[},right delimiter={]},draw=red!60,solid](\mC@secondarg){\scantokens{\relax##1}} node at ($(\mC@secondarg.north east)+(.25,0)$) {$\ddagger$};}
-  \renewcommand{\mC@arrow}[3][]{
-   \renewcommand{\mC@arrow@length@factor}{\mC@arrow@currentlength}
-   \setlength{\mC@arrow@length@actual}{\mC@arrow@currentlength\mC@arrow@length@value}
-   \ifthenelse{\equal{\mC@arrow@argument@both}{true}}{
-     \mC@largernode{##2}{##3}
-   }{
-     \setlength{\mC@arrow@argument@width}{0pt}
-     \setlength{\mC@arrow@argument@height}{0pt}
-   }
-   \draw node[solid,on chain=going \mC@arrow@currentdirection](\mC@arrow@currentname) {\tikz{
-     \mC@arrow@drawing
-     }
-   };
-   \mC@arrow@argument@anchor
-   \draw node[draw=green!60,solid,anchor=\mC@arrow@above@anchor,rotate=\mC@arrow@rotate,minimum width=\mC@arrow@argument@width, minimum height=\mC@arrow@argument@height]
-    at ($(@arrow@center.base)+(90+\mC@arrow@argument@angle:\mC@arrow@argument@aboveshift)$) {##2};
-   \draw node[draw=blue!60,solid,anchor=\mC@arrow@below@anchor,rotate=\mC@arrow@rotate,minimum width=\mC@arrow@argument@width, minimum height=\mC@arrow@argument@height]
-    at ($(@arrow@center.base)+(-90+\mC@arrow@argument@angle:\mC@arrow@argument@belowshift)$) {##3};
-   \setlength{\mC@arrow@argument@aboveshift}{2pt}
-   \setlength{\mC@arrow@argument@belowshift}{2pt}
-  }
+\let\mC@reactant@visible\@empty
+\let\mC@arrow@uplabel@visible\@empty
+\let\mC@arrow@downlabel@visible\@empty
+\let\mC@branch@visible\@empty
+\def\makevisible{
+  \def\mC@reactant@visible{draw=red!60,solid}
+  \def\mC@arrow@uplabel@visible{draw=green!60,solid}
+  \def\mC@arrow@downlabel@visible{draw=blue!60,solid}
+  \def\mC@branch@visible{draw=cyan,solid}
 }
-
-\newcommand\makeinvisible{
-  \def\mC@reactant@iii##1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg](\mC@secondarg){\scantokens{\relax##1}};}
-  \def\mC@branch@iii##1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg](\mC@secondarg){\tikzpicture[start branch]\scantokens{\relax##1}\endtikzpicture};}
-  \def\mC@transition@iii##1{\expandafter\expandafter\expandafter\node\expandafter\expandafter\expandafter[\expandafter\mC@firstarg\expandafter,\mC@thirdarg,inner sep=1pt,left delimiter={[},right delimiter={]}](\mC@secondarg){\scantokens{\relax##1}} node at ($(\mC@secondarg.north east)+(.25,0)$) {$\ddagger$};}
-  \renewcommand{\mC@arrow}[3][]{
-   \renewcommand{\mC@arrow@length@factor}{\mC@arrow@currentlength}
-   \setlength{\mC@arrow@length@actual}{\mC@arrow@currentlength\mC@arrow@length@value}
-   \ifthenelse{\equal{\mC@arrow@argument@both}{true}}{
-     \mC@largernode{##2}{##3}
-   }{
-     \setlength{\mC@arrow@argument@width}{0pt}
-     \setlength{\mC@arrow@argument@height}{0pt}
-   }
-   \draw node[on chain=going \mC@arrow@currentdirection](\mC@arrow@currentname) {\tikz{
-     \mC@arrow@drawing
-     }
-   };
-   \mC@arrow@argument@anchor
-   \draw node[anchor=\mC@arrow@above@anchor,rotate=\mC@arrow@rotate,minimum width=\mC@arrow@argument@width, minimum height=\mC@arrow@argument@height]
-    at ($(@arrow@center.base)+(90+\mC@arrow@argument@angle:\mC@arrow@argument@aboveshift)$) {##2};
-   \draw node[anchor=\mC@arrow@below@anchor,rotate=\mC@arrow@rotate,minimum width=\mC@arrow@argument@width, minimum height=\mC@arrow@argument@height]
-    at ($(@arrow@center.base)+(-90+\mC@arrow@argument@angle:\mC@arrow@argument@belowshift)$) {##3};
-   \setlength{\mC@arrow@argument@aboveshift}{2pt}
-   \setlength{\mC@arrow@argument@belowshift}{2pt}
-  }
+\def\makeinvisible{
+  \let\mC@reactant@visible\@empty
+  \let\mC@arrow@uplabel@visible\@empty
+  \let\mC@arrow@downlabel@visible\@empty
+  \let\mC@branch@visible\@empty
 }
 % ------------------------------------------------------------------------------------- %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%