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authorNorbert Preining <norbert@preining.info>2020-02-02 03:02:06 +0000
committerNorbert Preining <norbert@preining.info>2020-02-02 03:02:06 +0000
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-% !arara: pdflatex
-% !arara: biber
-% arara: pdflatex
-% arara: pdflatex
-% --------------------------------------------------------------------------
-% the CHEMFORMULA package
-%
-% typeset chemical compounds and reactions
-%
-% --------------------------------------------------------------------------
-% Clemens Niederberger
-% --------------------------------------------------------------------------
-% https://github.com/cgnieder/chemformula/
-% contact@mychemistry.eu
-% --------------------------------------------------------------------------
-% If you have any ideas, questions, suggestions or bugs to report, please
-% feel free to contact me.
-% --------------------------------------------------------------------------
-% Copyright 2011-2019 Clemens Niederberger
-%
-% This work may be distributed and/or modified under the
-% conditions of the LaTeX Project Public License, either version 1.3
-% of this license or (at your option) any later version.
-% The latest version of this license is in
-% http://www.latex-project.org/lppl.txt
-% and version 1.3 or later is part of all distributions of LaTeX
-% version 2005/12/01 or later.
-%
-% This work has the LPPL maintenance status `maintained'.
-%
-% The Current Maintainer of this work is Clemens Niederberger.
-% --------------------------------------------------------------------------
-\documentclass[load-preamble+]{cnltx-doc}
-\usepackage[utf8]{inputenc}
-\usepackage[T1]{fontenc}
-\usepackage{chemformula}
-\usepackage{chemmacros}
-\setcnltx{
- package = {chemformula},
- info = {typeset chemical compounds and reactions} ,
- url = http://www.mychemistry.eu/forums/forum/chemformula/ ,
- authors = Clemens Niederberger ,
- email = contact@mychemistry.eu ,
- abstract = {%
- \centering
- \includegraphics{chemmacros-logo.pdf}
- \par
- } ,
- add-cmds = {
- bond,
- ce, ch, charrow, chcpd, chemformula@bondlength, chemsetup, chlewis,
- chname,
- DeclareChemAdditionSymbol, DeclareChemArrow, DeclareChemBond,
- DeclareChemBondAlias, DeclareChemCompoundProperty, DeclareChemSymbol,
- mch,
- NewChemAdditionSymbol, NewChemArrow, NewChemBond, NewChemBondAlias,
- NewChemCompoundProperty, NewChemSymbol,
- ox, OX,
- pch,
- redox, RemoveChemCompoundProperty, RenewChemAdditionSymbol,
- RenewChemArrow, RenewChemBond, RenewChemCompoundProperty,
- RenewChemSymbol,
- setchemformula, ShowChemArrow, ShowChemBond
- } ,
- add-silent-cmds = {
- addplot,
- chemfig,
- DeclareInstance, draw,
- sample, setchemfig, sfrac,
- usetikzlibrary
- } ,
- index-setup = { othercode=\footnotesize, level=\section , noclearpage } ,
- makeindex-setup = { columns=3, columnsep=1em }
-}
-
-\usepackage{chemfig,booktabs,cancel,varioref}
-\usepackage[version=4]{mhchem}
-
-\makeatletter
-\def\libertine@figurestyle{LF}
-\RequirePackage{amsmath}
-\undef\lvert \undef\lVert
-\undef\rvert \undef\rVert
-\RequirePackage[libertine]{newtxmath}
-\def\libertine@figurestyle{OsF}
-\makeatother
-
-\chemsetup{
- greek = newtx ,
- modules = {redox,reactions,units} ,
- formula = chemformula ,
- chemformula/format = \libertineLF
-}
-
-\usepackage[biblatex]{embrac}
-\ChangeEmph{[}[,.02em]{]}[.055em,-.08em]
-\ChangeEmph{(}[-.01em,.04em]{)}[.04em,-.05em]
-\usepackage{csquotes}
-
-\usepackage[accsupp]{acro}
-\acsetup{
- long-format = \scshape ,
- short-format = \scshape
-}
-\DeclareAcronym{iupac}{
- short = iupac ,
- long = International Union of Pure and Applied Chemistry ,
- pdfstring = IUPAC ,
- accsupp = IUPAC
-}
-
-% \chemsetup{ option/synchronize }
-% \setchemformula{ format = \libertineLF }
-
-\sisetup{
- detect-mode=false,
- mode=text,
- text-rm=\libertineLF
-}
-
-\usepackage{filecontents}
-
-\defbibheading{bibliography}{\section{References}}
-\addbibresource{\jobname.bib}
-\begin{filecontents*}{\jobname.bib}
-@book{iupac:greenbook,
- author = {E. Richard Cohan and Tomislav Cvita\v{s} and Jeremy G. Frey and
- Bertil Holmstr\"om and Kozo Kuchitsu and Roberto Marquardt and Ian Mills and
- Franco Pavese and Martin Quack and J\"urgen Stohner and Herbert L. Strauss and
- Michio Takami and Anders J Thor} ,
- title = {``Quantities, Symbols and Units in Physical Chemistry'', \acs{iupac}
- Green Book} ,
- sorttitle = {Quantities, Symbols and Units in Physical Chemistry} ,
- indexsorttitle = {Quantities, Symbols and Units in Physical Chemistry} ,
- edition = {3rd Edition. 2nd Printing} ,
- year = {2008} ,
- publisher = {\acs{iupac} \&\ RSC Publishing, Cambridge}
-}
-\end{filecontents*}
-
-\DeclareInstance{xfrac}{chemformula-text-frac}{text}
- {
- scale-factor = 1 ,
- denominator-bot-sep = -.2ex ,
- denominator-format = \scriptsize #1 ,
- numerator-top-sep = -.2ex ,
- numerator-format = \scriptsize #1 ,
- slash-right-kern = .05em ,
- slash-left-kern = .05em
- }
-
-\newpackagename\chemmacros{chemmacros}
-
-\newidxcmd\manual{\textsf{#1}}[\ (manual)]
-\newidxcmd\arrowtype{\code{#1}}[\ (arrow type)]
-
-\makeatletter
-\newcommand*\cf@arrow{%
- \@ifstar
- {\cf@arrow@star}
- {\cf@arrow@nostar}%
-}
-\newrobustcmd*\cf@arrow@star[1]{%
- \@ifnextchar[
- {\cf@arrow@star@opt{#1}}
- {\cf@arrow@star@opt{#1}[]}%
-}
-\newrobustcmd*\cf@arrow@nostar[1]{%
- \@ifnextchar[
- {\cf@arrow@nostar@opt{#1}}
- {\cf@arrow@nostar@opt{#1}[]}%
-}
-\def\cf@arrow@star@opt#1[#2]{%
- \ifblank{#2}
- {\item\arrowtype*{#1}}
- {\item\arrowtype*{#1}#2}%
- \cnltx@checkdefault{\hfill\newline}%
-}
-\def\cf@arrow@nostar@opt#1[#2]{%
- \ifblank{#2}
- {\item\arrowtype{#1}}
- {\item\arrowtype{#1}#2}%
- \cnltx@checkdefault{\hfill\newline}%
-}
-
-\newenvironment{codedesc}
- {%
- \def\Code##1{\item\code{##1}\hfill\newline}%
- \cnltxlist
- }
- {\endcnltxlist}
-
-\newenvironment{arrows}
- {%
- \let\arrow\cf@arrow
- \cnltxlist
- }
- {\endcnltxlist}
-\makeatother
-
-\renewcommand*\AmS{\hologo{AmS}}
-
-\newcommand*\TikZ{Ti\textit{k}Z}
-
-\newname\hensel{Martin Hensel}
-
-\begin{document}
-
-\section{Introduction}
-Probably every chemist using \LaTeXe\ is aware of the great \pkg{mhchem}
-package by \hensel. There have always been some difficulties intertwining it
-with the \chemmacros\ package, though. Also, some other minor points in
-\pkg{mhchem} always bothered me, but they hardly seemed enough for a new
-package. They weren't even enough for a feature request to the \pkg{mhchem}
-author. The challenge and the fun of creating a new package and the wish for
-a highly customizable alternative led to \chemformula\ after all.
-
-\chemformula\ works very similar to \pkg{mhchem} but is more strict as to how
-compounds, stoichiometric factors and arrows are input. In the same time
-\chemformula\ offers \emph{many} possibilities to customize the output.
-
-\section{Licence and Requirements}
-\license
-
-The \chemformula\ package needs and thus loads the packages
-\bnd{l3kernel}~\cite{bnd:l3kernel}, \pkg{xparse}, \pkg{l3keys2e} and
-\pkg{xfrac} (all three are part of the \bnd{l3packages}
-bundle~\cite{bnd:l3packages}),
-\pkg{tikz}\footnote{\CTANurl[graphics]{pgf}}~\cite{pkg:pgf},
-\pkg{amstext}~\cite{pkg:amstext}, \pkg{nicefrac}~\cite{pkg:nicefrac} and
-\pkg{scrlfile} (from the \KOMAScript\footnote{\CTANurl{koma-script}}
-bundle~\cite{bnd:koma-script}).
-
-\section{Setup}
-
-If you're using \chemformula\ as a standalone package options are set up with
-the following command:
-\begin{commands}
- \command{setchemformula}[\marg{options}]
- Set up \chemformula.
-\end{commands}
-
-\chemformula\ is tightly intertwined with the \chemmacros\ package. If both
-packages are loaded together, \chemformula\ is integrated into the
-\chemmacros\ package. Then all of \chemformula's options belong to
-\chemmacros' module \module{chemformula}. This means if you load it via
-\chemmacros\ or in addition to \chemmacros\ they can be setup with
-\begin{commands}
- \command{chemsetup}[\Oarg{chemformula}\marg{options}]
- Set up options for \chemformula\ exclusively, or
- \command{chemsetup}[\Marg{chemformula/\meta{option1},chemformula/\meta{option2}}]
- Set up options for \chemformula\ together with others of \chemmacros'
- options.
-\end{commands}
-
-\section{The Basic Principle}
-\chemformula\ offers one main command.
-\begin{commands}
- \command{ch}[\oarg{options}\marg{input}]
- \chemformula's main command.
-\end{commands}
-The usage will seem very familiar to you if you're familiar with \pkg{mhchem}:
-\begin{example}[side-by-side]
- \ch{H2O} \par
- \ch{Sb2O3} \par
- \ch{H+} \par
- \ch{CrO4^2-} \par
- \ch{AgCl2-} \par
- \ch{[AgCl2]-} \par
- \ch{Y^{99}+} \par
- \ch{Y^{99+}} \par
- \ch{H2_{(aq)}} \par
- \ch{NO3-} \par
- \ch{(NH4)2S} \par
- \ch{^{227}_{90}Th+} \par
- $V_{\ch{H2O}}$ \par
- \ch{Ce^{IV}} \par
- \ch{KCr(SO4)2 * 12 H2O}
-\end{example}
-
-However, there are differences. The most notable one: \chemformula\
-distinguishes between different types of input. These different parts
-\emph{have} to be separated with blanks:
-\begin{commands}
- \command{ch}[\Marg{part1 part2 part3 part4}]
-\end{commands}
-A blank in the input \emph{never} is a blank in the output. This role of the
-blank strictly holds and disregarding it can have unexpected results and even
-lead to errors.
-
-The most visible differences regard spacing and the shapes of the default
-arrows:
-\begin{example}[side-by-side]
- \ch{A + B ->[a] C} \par
- \ce{A + B ->[a] C}
-\end{example}
-
-This means that \cs{ch}\Marg{2H2O} is recognized as a \emph{single} part,
-which in this case is recognized as a compound.
-\begin{example}[side-by-side]
- \ch{2H2O} \par
- \ch{2 H2O}
-\end{example}
-This also means, that a part cannot contain a blank since this will
-automatically divide it into two parts. If you need an extra blank in the
-output you need to use \verbcode+~+ or \cs*{~}. However, since commands
-in most cases gobble a space after them a input like
-\cs{ch}\Marg{\cs*{command} ABC} will be treated as a single part. If you want
-or need to divide them you need to add an empty group:
-\cs{ch}\Marg{\cs*{command}\marg{} ABC}. The different input types are
-described in the following sections.
-
-% % TODO: Module überdenken, Beschreibung anpassen
-% There are some options to customize the output of the \cs{ch} command. They
-% can either be applied locally using the optional argument or can be set
-% globally using the setup command. All options of \chemformula\ belong to the
-% module \module{chemformula} and can be set in different ways:
-% \begin{commands}
-% \command{chemsetup}[\Oarg{chemformula}\marg{options}]
-% when loaded via \chemmacros
-% \command{chemsetup}[\Marg{chemformula/\meta{options}}]
-% when loaded via \chemmacros
-% \command{setchemformula}[\marg{options}]
-% independent from \chemmacros
-% \end{commands}
-
-\section{Stoichiometric Factors}
-A stoichiometric factor may only contain of numbers and the signs
-\verbcode+.,_/()+
-\begin{example}[side-by-side]
- \ch{2} \par
- \ch{12}
-
- % decimals:
- \ch{.5} \par
- \ch{5,75}
-
- % fractions:
- \ch{3/2} \par
- \ch{1_1/2}
-
- % ``iupac'':
- \ch{(1/2)}
-\end{example}
-
-As you can see if you input decimal numbers a missing leading zero is added.
-
-You have to be a little bit careful with the right syntax but I believe it is
-rather intuitive.
-\begin{sourcecode}
- this won't work but will result in an error: \ch{1/1_1}
-\end{sourcecode}
-
-If stoichiometric factors are enclosed with parentheses the fractions are not
-recognized and missing leading zeros are not added. What's inside the
-parentheses is typeset as is.
-\begin{example}
- \ch{(1/2) H2O} \ch{1/2 H2O} \ch{0.5 H2O}
-\end{example}
-You can find many examples like the following for stoichiometric factors in
-parentheses in the \acs{iupac} Green Book~\cite{iupac:greenbook}:
-\begin{reaction*}
- (1/5) K "\ox{7,Mn}" O4 + (8/5) HCl == (1/5) "\ox{2,Mn}" Cl2 + (1/2) Cl2 + (1/5) KCl + (4/5) H2O
-\end{reaction*}
-
-There are a few possibilities to customize the output.
-\begin{options}
- \keyval{decimal-marker}{marker}\Default{.}
- The symbol to indicate the decimal.
- \keychoice{frac-style}{math,xfrac,nicefrac}\Default{math}
- Determines how fractions are displayed.
- \keyval{frac-math-cmd}{command sequence}\Default{\cs*{frac}}
- \sinceversion{4.1}Allows you to choose which command is used with
- \keyis{frac-style}{math}. This needs to be a command sequence that takes
- two arguments that are set in math mode.
- \keyval{stoich-space}{skip}\Default{.1667em plus .0333em minus .0117em}
- The space that is placed after the stoichiometric factor. A rubber
- length.
- \keybool{stoich-paren-parse}\Default{false}
- If set to true stoichiometric factors enclosed by parentheses also are
- parsed.
- \keyval{stoich-print}{cs}\Default{\cs{chstoich}}
- This option allows to redefine the macro that prints the stoichiometric
- factors. \meta{cs} should be a macro that takes one mandatory argument.
- \emph{Please note that using this option will disable \chemformula's
- stoichiometric parsing as that is done by the default command
- \cs{chstoich}.}
-\end{options}
-
-\begin{example}
- \ch[decimal-marker={,}]{3.5} \ch[decimal-marker={$\cdot$}]{3,5}
-\end{example}
-
-The option \keyis{frac-style}{xfrac} uses the \cs*{sfrac} command of the
-\pkg{xfrac} package. The output strongly depends on the font you use.
-\begin{example}
- \ch[frac-style=xfrac]{3/2} \ch[frac-style=xfrac]{1_1/2}
-\end{example}
-\chemformula\ defines the instance \code{chemformula-text-frac} which you can
-redefine to your needs. See the \pkg{xfrac} documentation for further
-information. The default definition is this:
-\begin{sourcecode}
- \DeclareInstance{xfrac}{chemformula-text-frac}{text}
- {
- slash-left-kern = -.15em ,
- slash-right-kern = -.15em
- }
-\end{sourcecode}
-This document uses the font Linux Libertine~O and the following definition:
-\begin{sourcecode}
- \DeclareInstance{xfrac}{chemformula-text-frac}{text}
- {
- scale-factor = 1 ,
- denominator-bot-sep = -.2ex ,
- denominator-format = \scriptsize #1 ,
- numerator-top-sep = -.2ex ,
- numerator-format = \scriptsize #1 ,
- slash-right-kern = .05em ,
- slash-left-kern = .05em
- }
-\end{sourcecode}
-
-The option \keyis{frac-style}{nicefrac} uses the \cs*{nicefrac} command of the
-\pkg{nicefrac} package.
-\begin{example}
- \ch[frac-style=nicefrac]{3/2} \ch[frac-style=nicefrac]{1_1/2}
-\end{example}
-
-The option \option{stoich-space} allows you to customize the space between
-stoichiometric factor and the group following after it.
-\begin{example}[side-by-side]
- \ch{2 H2O} \par
- \ch[stoich-space=.3em]{2 H2O}
-\end{example}
-
-\section{Compounds}\label{ssec:compounds}
-\chemformula\ determines compounds as the type that ``doesn't fit in anywhere
-else.'' This point will become more clear when you know what the other types
-are.
-\begin{example}[side-by-side]
- \ch{H2SO4} \par
- \ch{[Cu(NH3)4]^2+}
-\end{example}
-
-\subsection{Adducts}
-\chemformula\ has two identifiers which will create adducts.
-\begin{commands}
- \command{ch}[\Marg{A.B}] \ch{A.B}
- \command{ch}[\Marg{A*B}] \ch{A*B}
-\end{commands}
-\begin{example}[side-by-side]
- \ch{CaSO4.H2O} \par
- \ch{CaSO4*H2O}
-\end{example}
-Since numbers in a compound always are treated as subscripts (see
-section~\ref{ssec:subscripts}) you sometimes need to introduce stoichiometric
-factors for the right output:
-\begin{example}[side-by-side]
- \ch{Na3PO4*12H2O} \par
- \ch{Na3PO4* 12 H2O} \par
- \ch{Na3PO4 * 12 H2O}
-\end{example}
-
-\subsection{Subscripts}\label{ssec:subscripts}
-\emph{All} numbers in a compound are treated as subscripts.
-\begin{example}[side-by-side]
- \ch{H2SO4}
-\end{example}
-If you want a letter to be a subscript you can use the math syntax:
-\begin{example}[side-by-side]
- \ch{A_nB_m}
-\end{example}
-The subscript recognizes groups. You can also use math inside it.
-\begin{example}[side-by-side]
- \ch{A_{$n$}B_{$m$}} \par
- \ch{NaCl_{(aq)}}
-\end{example}
-
-\subsection{Commands}
-Commands are allowed in a compound:
-\begin{example}[side-by-side]
- \ch{\textbf{A2}B3} \ch{A2\color{red}B3}
-\end{example}
-
-However, if the commands demand numbers as argument, \eg, space commands or
-\chemmacros' \verbcode+\ox+ command the direct use will fail. This is
-because the numbers are treated as subscripts \emph{before} the command
-expands.
-\begin{sourcecode}
- \ch{A\hspace{2mm}B} will raise an error because \hspace sees something like
- this: \hspace{$_2$mm}. Actually not at all like this but equally bad\ldots
-\end{sourcecode}
-See section~\ref{ssec:text} for a way around this.
-
-Please also note that formulas are placed inside a group!
-\begin{example}[side-by-side]
- \ch{A2\color{red}B3 C4}
-\end{example}
-
-\subsection{Charges and Other Superscripts}
-\paragraph{Basics}
-If a compound \emph{ends} with a plus or minus sign it will be treated as
-charge sign and typeset as superscript. In other places a plus is treated as
-a triple bond and a dash will be used as a single bond, see
-section~\ref{ssec:bonds}.
-\begin{example}[side-by-side]
- \ch{A+B} \ch{AB+} \par
- \ch{A-B} \ch{AB-}
-\end{example}
-
-For longer charge groups or other superscripts you can use the math syntax.
-It recognizes groups and you can use math inside them. Inside these groups
-neither \code{+} nor \code{-} are treated as bonds. If a dot \code{.} is
-inside a superscript it is treated as indicator for a radical. A \code{*}
-gives the excited state.
-\begin{example}[side-by-side]
- \ch{A^{x-}} \par
- \ch{A^x-} \par
- \ch{A^{x}-} \par
- \ch{A^{$x-$}} \par
- \ch{RNO2^{-.}} \par
- \ch{^31H} \par
- \ch{^{14}6C} \par
- \ch{^{58}_{26}Fe} \par
- \ch{NO^*}
-\end{example}
-
-Actually\changedversion{4.5a} a dot \code{.} is not always treated as
-indicator for a radical: if the dot in the superscript is followed by a number
-it is interpreted as a decimal sign. It is typeset according to the option
-\option{decimal-marker}. This may be a good place to mention that a comma
-\code{,} in a superscript is also typeset according to
-\option{decimal-marker}.
-
-\begin{example}[side-by-side]
- \ch{^{22,98}_{11}Na}
- \ch{^{22.98}_{11}Na}\par
- \setchemformula{decimal-marker={,}}
- \ch{^{22,98}_{11}Na}
- \ch{^{22.98}_{11}Na}
-\end{example}
-
-Ions and ion composites with more than one charge can be typeset quite as
-easy:
-\begin{example}[side-by-side]
- \ch{SO4^2-} \ch{Ca^2+ SO4^2-}
-\end{example}
-
-\paragraph{Charge Commands}
-You don't need to use \cs{mch} and related commands inside \cs{ch}. Indeed,
-you \emph{shouldn't} use them as they might mess with the subscript and
-superscript alignment. The \chemmacros\ option \code{circled} is obeyed by
-\cs{ch}.
-\begin{example}
- \chemsetup[charges]{circled=all}
- \ch{H+ + OH- <=> H2O}
-\end{example}
-
-\chemformula\ knows the options \option{circled} and \option{circletype} also
-on its own.
-
-\begin{example}
- \setchemformula{circled=all}
- \ch{H+ + OH- <=> H2O}
-\end{example}
-
-These options are coupled with \chemmacros\ options, \ie, setting \chemmacros'
-options will also set \chemformula's equivalents. The other way around the
-options act independently: setting \chemformula's options will \emph{not} set
-\chemmacros' options.
-\begin{options}
- \keychoice{circled}{formal,\default{all},none}\Default{formal}
- \chemformula\ uses two different kinds of charges which indicate the usage
- of real ($+/-$) and formal (\fplus/\fminus) charges. The choice
- \code{formal} distinguishes between them, choice \code{none} displays them
- all without circle, choice \code{all} circles all.
- % circletype
- \keychoice{circletype}{\default{chem},math}\Default{chem}
- This option switches between two kinds of circled charge symbols:
- \cs{fplus} \fplus\ and \verbcode+$\oplus$+ $\oplus$.
-\end{options}
-
-\paragraph{Behaviour}
-The supercripts behave differently depending on their position in a compound,
-if there are super- and subscripts following each other directly.
-\begin{example}
- \ch{^33B} \ch{{}^33B} \ch{3^3B} \ch{B^3} \ch{B3^3} \par
- \ch{^{23}_{123}B} \ch{{}^{23}_{123}B} \ch{_{123}^{23}B}
- \ch{B^{23}} \ch{B_{123}^{23}} \par
- \ch{^{123}_{23}B} \ch{{}^{123}_{23}B} \ch{_{23}^{123}B}
- \ch{B^{123}} \ch{B23^{123}}
-\end{example}
-\begin{itemize}
- \item If a compound \emph{starts} with a sub- or superscript both sub- and
- superscript are aligned to the \emph{right} else to the \emph{left}.
- \item If a compound \emph{does not start} with a sub- or superscript and
- there is both a sub- and a superscript, the superscript is shifted
- additionally by a length determined from the option
- \key{charge-hshift}{dim}, also see page~\pageref{desc:charge-hshift}f.
-\end{itemize}
-The second point follows \ac{iupac}'s recommendations:
-\begin{cnltxquote}[{\acs{iupac} Green Book {\cite[][p.\,51]{iupac:greenbook}}}]
- In writing the formula for a complex ion, spacing for charge number can be
- added (staggered arrangement), as well as parentheses:
- \ch[charge-hshift=full]{SO4^2-}, \ch{(SO4)^2-}. The staggered arrangement
- is now recommended.
-\end{cnltxquote}
-
-\subsection{Bonds}\label{ssec:bonds}
-\subsubsection{Native Bonds}
-There are three kinds of what I will call ``native bonds'':
-\begin{example}[side-by-side]
- single: \ch{CH3-CH3} \par
- double: \ch{CH2=CH2} \par
- triple: \ch{CH+CH}
-\end{example}
-
-\subsubsection{Flexible Bonds}
-\paragraph{Predefined Bonds}
-In addition to the three native bonds there are a few more which can be called
-by
-\begin{commands}
- \command{bond}[\marg{bond name}]
- Prints the bond type specified by \meta{bond name}.
-\end{commands}
-The predefined bond types are shown in table~\vref{tab:bond_types}.
-
-\begin{table}
- \centering
- \caption{Bonds available with \cs*{bond}.}
- \label{tab:bond_types}
- \begin{tabular}{lcl}
- \toprule
- \bfseries name & \bfseries appearance & \bfseries aliases \\
- \midrule
- \code{single} & \bond{single} & \code{normal}, \code{sb} \\
- \code{double} & \bond{double} & \code{db} \\
- \code{triple} & \bond{triple} & \code{tp} \\
- \code{dotted} & \bond{dotted} & \code{semisingle} \\
- \code{deloc} & \bond{deloc} & \code{semidouble} \\
- \code{tdeloc} & \bond{tdeloc} & \code{semitriple} \\
- \code{co>} & \bond{co>} & \code{coordright} \\
- \code{<co} & \bond{<co} & \code{coordleft} \\
- \bottomrule
- \end{tabular}
-\end{table}
-
-\begin{example}
- \ch{C\bond{sb}C\bond{db}C\bond{tp}C\bond{deloc}C\bond{tdeloc}C\bond{co>}C\bond{<co}C}
-\end{example}
-
-\paragraph{Own Bonds}
-\chemformula{} offers commands to define own bond types:
-\begin{commands}
- \command{NewChemBond}[\marg{name}\marg{code}]
- \sinceversion{4.3}Define the new bond type \meta{name}. Issue an error if
- a bond \meta{name} already exists.
- \command{DeclareChemBond}[\marg{name}\marg{code}]
- Define the new bond type \meta{name} or overwrite it if it already
- exists.
- \command{RenewChemBond}[\marg{name}\marg{code}]
- Redefine the existing bond type \meta{name}. Issue an error if a bond
- \meta{name} doesn't exist.
- \command{ProvideChemBond}[\marg{name}\marg{code}]
- \sinceversion{4.12a}Define the new bond type \meta{name} only if it
- doesn't exist yet.
- \command{NewChemBondAlias}[\marg{new name}\marg{old name}]
- \sinceversion{4.3}Declare the bond type \meta{new name} to be an alias of
- \meta{old name}. Issue an error if a bond \meta{new name} already
- exists.
- \command{DeclareChemBondAlias}[\marg{new name}\marg{old name}]
- Declare the bond type \meta{new name} to be an alias of \meta{old name}.
- \command{ShowChemBond}[\marg{name}]
- Print the definition of bond type \meta{name}.
-\end{commands}
-The usage is best described with an example. So let's see how the
-\code{single} bond and the \code{co>} bond are defined:
-\begin{sourcecode}
- \NewChemBond{single}
- { \draw[chembond] (chemformula-bond-start) -- (chemformula-bond-end) ; }
- \NewChemBond{coordright}
- {
- \draw[chembond,butt cap->]
- (chemformula-bond-start) -- (chemformula-bond-end) ;
- }
- \NewChemBondAlias{co>}{coordright}
-\end{sourcecode}
-Two points are important: the names of the starting and the ending
-coordinates, \code{chemformula-bond-start} and \code{chemformula-bond-end},
-and the \TikZ\ style of the bonds \code{chembond}.
-
-So, let's say you want to define a special kind of dashed bond. You could do
-this:
-\begin{example}
- \usetikzlibrary{decorations.pathreplacing}
- \makeatletter
- \NewChemBond{dashed}
- {
- \draw[
- chembond,
- decorate,
- decoration={
- ticks,
- segment length=\chemformula@bondlength/10,amplitude=1.5pt
- }]
- (chemformula-bond-start) -- (chemformula-bond-end) ;
- }
- \makeatother
- \setchemformula{bond-length=2ex}
- \ch{C\bond{dashed}C}
-\end{example}
-
-The last example showed you another macro: \verbcode+\chemformula@bondlength+.
-It only exists so you can use it to access the bond length as set with
-\option{bond-length} directly.
-
-\subsection{Customization}\label{ssec:compounds:customization}
-These options allow you to customize the ouptut of the compounds:
-\begin{options}
- \keyval{subscript-vshift}{dim}\Default{0pt}
- Extra vertical shift of the subscripts.
- \keychoice{subscript-style}{text,math}\Default{text}
- Style that is used to typeset the subscripts.
- \keyval{charge-hshift}{dim}\Default{.25em}
- Shift of superscripts when following a subscript.\label{desc:charge-hshift}
- \keyval{charge-vshift}{dim}\Default{0pt}
- Extra vertical shift of the superscripts.
- \keychoice{charge-style}{text,math}\Default{text}
- Style that is used to typeset the superscripts.
- \keychoice{circled}{formal,\default{all},none}\Default{formal}
- \sinceversion{4.6}Like \chemmacros' package option but local to
- \chemformula's \cs{ch}. That is: since \chemmacros' macros use
- \chemformula's mechanism this is effectively an alias.
- \keychoice{circletype}{\default{chem},math}\Default{chem}
- \sinceversion{4.6}Like \chemmacros' package option but local to
- \chemformula's \cs{ch}. That is: since \chemmacros' macros use
- \chemformula's mechanism this is effectively an alias.
- \keyval{adduct-space}{dim}\Default{.1333em}
- Space to the left and the right of the adduct point.
- \keyval{adduct-penalty}{num}\Default{300}
- The\sinceversion{4.14} penalty inserted after the adduct point for
- (dis-)allowing line breaks.
- \keyval{bond-length}{dim}\Default{.5833em}
- The length of the bonds.
- \keyval{bond-offset}{dim}\Default{.07em}
- Space between bond and atoms.
- \keyval{bond-style}{\TikZ}\Default
- \TikZ\ options for the bonds.
- \keyval{bond-penalty}{num}\Default{10000}
- \sinceversion{4.0a}The penalty that is inserted after a bond for
- (dis-)allowing line breaks.
- \keyval{radical-style}{\TikZ}\Default
- \TikZ\ options for the radical point.
- \keyval{radical-radius}{dim}\Default{.2ex}
- The radius of the radical point.
- \keyval{radical-hshift}{dim}\Default{.15em}
- Horizontal shift before the radical point is drawn.
- \keyval{radical-vshift}{dim}\Default{.5ex}
- Vertical shift relative to the current baseline.
- \keyval{radical-space}{dim}\Default{.15em}
- Horizontal shift after the radical point is drawn.
-\end{options}
-
-Maybe you have noticed that charges of certain ions are shifted to the
-right.
-\begin{example}[side-by-side]
- \ch{SO4^2-} \ch{NH4+} \ch{Na+}
-\end{example}
-They are shifted if they \emph{follow} a subscript which follows \ac{iupac}
-recommendations~\cite[][p.\,51]{iupac:greenbook}. The amount of the shift can
-be set with the option \option{charge-hshift}.
-\begin{example}
- \ch{SO4^2-} \ch{NH4+} \ch{Na+} \par
- \setchemformula{charge-hshift=.5ex}
- \ch{SO4^2-} \ch{NH4+} \ch{Na+} \par
- \setchemformula{charge-hshift=.5pt}
- \ch{SO4^2-} \ch{NH4+} \ch{Na+}
-\end{example}
-
-Despite \ac{iupac}'s recommendation \chemformula\ does not make fully staggered
-arrangements in the default setting as I find it hard to read in some cases
-and ugly in others. Since this is a subjective decision \chemformula\ not only
-let's you define the absolute amount of the shift but also provides a
-possibility for full staggered arrangements. For this you have to use
-\keyis{charge-hshift}{full}.
-\begin{example}
- \ch[charge-hshift=0pt]{C5H11+} \ch[charge-hshift=0pt]{SO4^2-} \par
- \ch{C5H11+} \ch{SO4^2-} \par
- \ch[charge-hshift=1ex]{C5H11+} \ch[charge-hshift=1ex]{SO4^2-} \par
- \ch[charge-hshift=full]{C5H11+} \ch[charge-hshift=full]{SO4^2-}
-\end{example}
-
-If you don't want the charges to be typeset in text mode you can switch to
-math mode:
-\begin{example}
- \ch{M^x+} \ch{SO4^2-} \par
- \setchemformula{charge-style = math}
- \ch{M^x+} \ch{SO4^2-}
-\end{example}
-
-The option \option{subscript-vshift} can be used to adjust the vertical shift
-of the subscripts:
-\begin{example}
- \ch{H2SO4} \ch{Na3PO4} \par
- \setchemformula{subscript-vshift=.5ex}
- \ch{H2SO4} \ch{Na3PO4} \par
- \setchemformula{subscript-vshift=-.2ex}
- \ch{H2SO4} \ch{Na3PO4}
-\end{example}
-
-You can choose the mode subscripts are typeset in the same way as it is
-possible for the charges:
-\begin{example}
- \ch{A_nB_m} \ch{H2SO4} \par
- \setchemformula{subscript-style = math}
- \ch{A_nB_m} \ch{H2SO4}
-\end{example}
-
-The option \option{adduct-space} sets the space left and right to the adduct
-symbol $\cdot$.
-\begin{example}
- \ch{Na3PO3*H2O} \par
- \setchemformula{adduct-space=.2em}
- \ch{Na3PO3*H2O}
-\end{example}
-
-Changing the length of the bonds:
-\begin{example}
- \setchemformula{bond-length=4mm}%
- single: \ch{CH3-CH3} \par
- double: \ch{CH2=CH2} \par
- triple: \ch{CH+CH}
-\end{example}
-
-You can change the distance between bond and atom, too:
-\begin{example}
- \ch{H-H + N+N + O=O} \par
- \ch[bond-offset=1pt]{H-H + N+N + O=O}
-\end{example}
-
-\subsection{Standalone Formulae}
-\chemformula\sinceversion{4.0} offers a command that \emph{only accepts} the
-\enquote{compound} input type:
-\begin{commands}
- \command{chcpd}[\oarg{options}\marg{compound}]
- Typeset single compounds.
-\end{commands}
-
-\subsection{Extend Compound Properties}\label{sec:extend-comp-prop}
-
-It\sinceversion{4.10} is possible to extend the range of special input symbols
-within compounds. In the default setting those are \verbcode|*.-=+'| and
-arabic numerals. Others can be added or the existing ones be changed with one
-of the following commmands:
-\begin{commands}
- \command{NewChemCompoundProperty}[\marg{token}\marg{replacement}]
- \meta{token} will be replaced by \meta{replacement} within compounds. The
- property is only added if \meta{token} is not yet part the compounds'
- property list. Otherwise an error is issued.
- \command{ProvideChemCompoundProperty}[\marg{token}\marg{replacement}]
- \meta{token}\sinceversion{4.12a} will be replaced by \meta{replacement}
- within compounds. The property is only added if \meta{token} is not yet
- part the compounds' property list.
- \command{RenewChemCompoundProperty}[\marg{token}\marg{replacement}]
- \meta{token} will be replaced by \meta{replacement} within compounds. The
- property is only added if \meta{token} is already part the compounds'
- property list. Otherwise an error is issued.
- \command{DeclareChemCompoundProperty}[\marg{token}\marg{replacement}]
- \meta{token} will be replaced by \meta{replacement} within compounds. The
- property silently overwrites any previously set \meta{replacement} for
- \meta{token} if \meta{token} is already part the compounds' property
- list.
- \command{RemoveChemCompoundProperty}[\marg{token}]
- Removes \meta{token} from the compounds' property list.
-\end{commands}
-
-For example you can use
-\begin{sourcecode}
- \NewChemCompoundProperty{\}{\slash}
-\end{sourcecode}
-to allow line breaks after slashes in compounds.
-
-\section{Special Input Types}
-There are some \enquote{special type} input groups.
-
-\subsection{Single Token Groups}
-The first kind are groups which consist of only one token. They are again
-divided into two groups, \enquote{addition symbols} and \enquote{symbols}.
-
-\subsubsection{Addition Symbols}\label{sec:addition-symbols}
-\begin{commands}
- \command{ch}[\Marg{ + } \ch{ + }]
- Creates the plus sign between compounds with space around it:\\
- \cs{ch}\Marg{2 Na + Cl2} \ch{2 Na + Cl2}
- \command{ch}[\Marg{ - } \ch{ - }]
- \sinceversion{4.3a}Creates the minus sign between compounds with space
- around it:\\
- \cs{ch}\Marg{M - H} \ch{M - H}
-\end{commands}
-Addition symbols are surrounded with space which can be customized according
-to options explained in a bit. There is also some penalty prohibiting a line
-break after them which also can be customized with an option.
-
-You can define/redefine your own addition symbols:
-\begin{commands}
- \command{NewChemAdditionSymbol}[\marg{name}\marg{input}\marg{output}]
- Defines\sinceversion{4.11} the addition symbol \meta{name} with input
- symbol \meta{input} and output \meta{output}.
- \command{ProvideChemAdditionSymbol}[\marg{name}\marg{input}\marg{output}]
- Defines\sinceversion{4.12a} the addition symbol \meta{name} with input
- symbol \meta{input} and output \meta{output} only no addition symbol with
- then name \meta{name} doesn't exist.
- \command{RenewChemAdditionSymbol}[\marg{name}\marg{input}\marg{output}]
- Redefines\sinceversion{4.11} the addition symbol \meta{name} with input
- symbol \meta{input} and output \meta{output}.
- \command{DeclareChemAdditionSymbol}[\marg{name}\marg{input}\marg{output}]
- (Re-)Defines\sinceversion{4.11} the addition symbol \meta{name} with input
- symbol \meta{input} and output \meta{output} without checking if the
- symbol exists or not.
-\end{commands}
-
-The space left and right of the plus and the minus sign and the signs
-themselves can be set with the following options:
-\begin{options}
- \keyval{plus-space}{skip}\Default{.3em plus .1em minus .1em}
- A rubber length.
- \keyval{plus-penalty}{num}\Default{700}
- \sinceversion{4.0a}The penalty that is inserted after the plus sign for
- (dis-)allowing line breaks.
- \keyval{plus-output-symbol}{code}\Default{+}
- \sinceversion{4.9}The \meta{code} that is used for the plus sign.
- \keyval{minus-space}{skip}\Default{.3em plus .1em minus .1em}
- \sinceversion{4.9}A rubber length.
- \keyval{minus-penalty}{num}\Default{700}
- \sinceversion{4.9}The penalty that is inserted after the minus sign for
- (dis-)allowing line breaks.
- \keyval{minus-output-symbol}{code}\Default{\$-\$}
- \sinceversion{4.9}The \meta{code} that is used for the minus sign.
-\end{options}
-The corresponding three options are defined when \cs{NewChemAdditionSymbol}
-or one of the variants is used, \code{\meta{name}-space} and
-\code{\meta{name}-penalty} both with the same defaults as above, and
-\code{\meta{name}-output-symbol}.
-
-\begin{example}[side-by-side]
- \ch{A + B}\par
- \ch[plus-space=4pt]{A + B}
-\end{example}
-
-\subsubsection{Symbols}\label{sec:symbols}
-\begin{commands}
- \command{ch}[\Marg{ v } \ch{ v }]
- Sign for precipitate: \cs{ch}\Marg{BaSO4 v} \ch{BaSO4 v}
- \command{ch}[\Marg{ \textasciicircum\ } \ch{ ^ }]
- Sign for escaping gas\footnotemark: \cs{ch}\Marg{H2 \textasciicircum}
- \ch{H2 ^}
-\end{commands}
-\footnotetext{Is this the correct English term? Please correct me if it isn't.}
-
-You can define/redefine your own symbols:
-\begin{commands}
- \command{NewChemSymbol}[\marg{input}\marg{output}]
- Defines\sinceversion{4.11} the addition symbol with input \meta{input} and
- output \meta{output}.
- \command{ProvideChemSymbol}[\marg{input}\marg{output}]
- Defines\sinceversion{4.12a} the addition symbol with input \meta{input} and
- output \meta{output} only if no symbol with input \meta{input} exists.
- \command{RenewChemSymbol}[\marg{input}\marg{output}]
- Redefines\sinceversion{4.11} the addition symbol with input \meta{input}
- and output \meta{output}.
- \command{DeclareChemSymbol}[\marg{input}\marg{output}]
- (Re-)Defines\sinceversion{4.11} the addition symbol with input
- \meta{input} and output \meta{output} without checking if the symbol
- exists or not.
-\end{commands}
-
-\subsection{Option Input}
-Sometimes you might want to apply an option only to a part of a, say,
-reaction. Of course you have the possibility to use \cs{ch} several times.
-\begin{example}
- \ch{H2O +}\textcolor{red}{\ch{H2SO4}}\ch{-> H3O+ + HSO4-} \par
- \ch{H2O +}\ch[subscript-vshift=2pt]{H2SO4}\ch{-> H3O+ + HSO4-}
-\end{example}
-This, however, interrupts the input in your source and \emph{may} mess with
-the spacing. That's why there is an alternative:
-\begin{commands}
- \command{ch}[\Marg{ @\marg{options} }]
- The options specified this way will be valid \emph{only} until the next
- compound is set.
-\end{commands}
-\begin{example}
- \ch{H2O +}\textcolor{red}{\ch{H2SO4}}\ch{-> H3O+ + HSO4-} \par
- \ch{H2O + @{format=\color{red}} H2SO4 -> H3O+ + HSO4-} \par
- or of course:\par
- \ch{H2O + \textcolor{red}{H2SO4} -> H3O+ + HSO4-}\par\bigskip
- \ch{H2O +}\ch[subscript-vshift=2pt]{H2SO4}\ch{-> H3O+ + HSO4-} \par
- \ch{H2O + @{subscript-vshift=2pt} H2SO4 -> H3O+ + HSO4-}
-\end{example}
-
-\section{Escaped Input}
-In some cases it may be desirable to prevent \chemformula\ from parsing the
-input. This can be done in two ways.
-
-\subsection{Text}\label{ssec:text}
-If you put something between \verbcode+" "+ or \verbcode+' '+ then the input
-will be treated as normal text, except that spaces are not allowed and have to
-be input with \verbcode+~+.
-\begin{commands}
- \command{ch}[\Marg{ "\meta{escaped text}" }]
- One of two possibilities to \emph{escape} \chemformula's parsing.
- \command{ch}[\Marg{ \textquotesingle\meta{escaped text}\textquotesingle\ }]
- The second of two possibilities to \emph{escape} \chemformula's parsing.
-\end{commands}
-\begin{example}[add-sourcecode-options={literate=}]
- \ch{"\ox{2,Ca}" O} \par
- \ch{"\ldots\," Na + "\ldots\," Cl2 -> "\ldots\," NaCl} \par
- \ch{'A~->~B'}
-\end{example}
-In many cases you won't need to escape the input. But when you get into
-trouble when using a command inside \cs{ch} try hiding it.
-
-\subsection{Math}
-If you especially want to input math you just enclose it with \verbcode+$ $+.
-This output is different from the escaped text as it is followed by a space.
-The reasoning behind this is that I assume math will mostly be used to replace
-stoichiometric factors.
-\begin{commands}
- \command{ch}[\Marg{ \string$\meta{escaped math}\string$ }]
- One of two possibilities to \emph{escape} \chemformula's parsing into math
- mode.
- \command{ch}[\Marg{ \string\(\meta{escaped math}\string\) }]
- The second of two possibilities to \emph{escape} \chemformula's parsing
- into math mode.
-\end{commands}
-\begin{example}[side-by-side]
- escaped text: \ch{"$x$" H2O} \par
- escaped math: \ch{$x$ H2O} \par
- also escaped math: \ch{\(x\) H2O} \par
- \ch{$2n$ Na + $n$ Cl2 -> $2n$ NaCl}
-\end{example}
-
-The space that is inserted after a math group can be edited:
-\begin{options}
- \keyval{math-space}{skip}\Default{.1667em plus .0333em minus .0117em}
- A rubber length.
-\end{options}
-\begin{example}
- \ch{$2n$ Na + $n$ Cl2 -> $2n$ NaCl} \par
- \setchemformula{math-space=.25em}
- \ch{$2n$ Na + $n$ Cl2 -> $2n$ NaCl} \par
- \ch{$A->B$}
-\end{example}
-
-\section{Arrows}\label{sec:arrows}
-\subsection{Arrow types}
-Arrows are input in the same intuitive way they are with \pkg{mhchem}.
-There are various different types:
-\begin{arrows}
- \arrow{->}[ \charrow{->}]
- standard right arrow
- \arrow{<-}[ \charrow{<-}]
- standard left arrow
- \arrow{-/>}[ \charrow{-/>}]
- does not react (right)
- \arrow{</-}[ \charrow{</-}]
- does not react (left)
- \arrow{<->}[ \charrow{<->}]
- resonance arrow
- \arrow{<>}[ \charrow{<>}]
- reaction in both directions
- \arrow{==}[ \charrow{==}]
- stoichiometric equation
- \arrow{<=>}[ \charrow{<=>}]
- equilibrium arrow
- \arrow{>=<}[ \charrow{>=<}]
- \sinceversion{4.5}reversed equilibrium arrow
- \arrow{<=>{}>}[ \charrow{<=>>}]
- unbalanced equilibrium arrow to the right
- \arrow{>=<{}<}[ \charrow{>=<<}]
- \sinceversion{4.5}reversed unbalanced equilibrium arrow to the right
- \arrow{<{}<=>}[ \charrow{<<=>}]
- unbalanced equilibrium arrow to the left
- \arrow{>{}>=<}[ \charrow{>>=<}]
- \sinceversion{4.5}reversed unbalanced equilibrium arrow to the left
- \arrow{<=o>}[ \charrow{<=o>}]
- \sinceversion{4.15}quasi equilibrium arrow
- \arrow{<=o>{}>}[ \charrow{<=o>>}]
- \sinceversion{4.15}unbalanced quasi equilibrium arrow to the right
- \arrow{<{}<=o>}[ \charrow{<<=o>}]
- \sinceversion{4.15}unbalanced quasi equilibrium arrow to the left
- \arrow{<o>}[ \charrow{<o>}]
- isolobal arrow
- \arrow{<==>}[ \charrow{<==>}]
- \sinceversion{4.5}I've seen this one used. I'm not sure it actually has a
- meaning in chemical equations. If you have some official reference for
- this arrow type please feel free to contact me.
-\end{arrows}
-All these arrows are drawn with \TikZ.
-\begin{example}
- \ch{H2 + Cl2 -> 2 HCl} \par
- \ch{H2O + CO3^2- <=> OH- + HCO3-} \par
- \ch{A <- B} \par
- \ch{\{[CH2=CH-CH2]- <-> {}[CH2-CH=CH2]- \}} \par
- \ch{A <> B} \par
- \ch{H+ + OH- <=>> H2O} \par
- \ch{2 NO2 <<=> N2O4}
-\end{example}
-
-\subsection{Labels}
-The arrows take two optional arguments to label them.
-\begin{arrows}
- \arrow*{->\oarg{above}\oarg{below}}
- Add text above or under an arrow.
-\end{arrows}
-\begin{example}[side-by-side]
- \ch{A ->[a] B} \par
- \ch{A ->[a][b] B} \par
- \ch{A ->[\SI{100}{\celsius}] B}
-\end{example}
-The label text can be parsed seperately from the arrow. The recipe is easy:
-leave blanks.
-\begin{example}[side-by-side]
- \ch{A ->[H2O] B} \par
- \ch{A ->[ H2O ] B} \par
- \ch{A ->[ "\ox{2,Ca}" F2 ] B} \par
- \ch{A ->[ $\Delta$,~ [ H+ ]] B}
-\end{example}
-
-If you leave the blanks \chemformula\ treats the groups inside the square
-brackets as seperated input types. The arrow reads its arguments
-\emph{afterwards}. As you can see the arrows \enquote{grow} with the length
-of the labels. What stays constant is the part that protrudes the labels.
-\begin{example}
- \ch{A ->[a] B} \par
- \ch{A ->[ab] B} \par
- \ch{A ->[abc] B} \par
- \ch{A ->[abc~abc] B} \par
- % needs the `chemfig' package:
- \setchemfig{atom sep =15pt}
- \ch{A ->[ "\chemfig{-[:30]-[:-30]OH}" ] B} \par
-\end{example}
-
-\subsection{Customization}
-These are the options which enable you to customize the arrows:
-\begin{options}
- \keyval{arrow-offset}{dim}\Default{.75em}
- This is the length that an arrow protrudes a label on both sides. This
- means an empty arrow's length is two times \code{arrow-offset}.
- \keyval{arrow-min-length}{dim}\Default{0pt}
- \sinceversion{3.6b}The minimal length an error must have unless two times
- \option{arrow-offset} plus the width of the label is larger.
- \keyval{arrow-yshift}{dim}\Default{0pt}
- Shifts an arrow up (positive value) or down (negative value).
- \keyval{arrow-ratio}{<factor>}\Default{.6}
- The ratio of the arrow lengths of the unbalanced equilibrium. \code{.4}
- would mean that the length of the shorter arrow is $0.4\times$ the length
- of the longer arrow.
- \keyval{compound-sep}{dim}\Default{.5em}
- The space between compounds and the arrows.
- \keyval{label-offset}{dim}\Default{2pt}
- The space between the labels and the arrows.
- \keyval{label-style}{font command}\Default{\cs*{footnotesize}}
- The relative font size of the labels.
- \keyval{arrow-penalty}{num}\Default{0}
- \sinceversion{4.0a}The penalty that is inserted after an arrow for
- (dis-)allowing line breaks.
- \keyval{arrow-style}{\TikZ}\Default
- \sinceversion{4.1a}Additonal \TikZ\ keys for formatting the arrows.
-\end{options}
-
-The following code shows the effect of the different options on the \verbcode+<=>>+
-arrow:
-\begin{example}
- standard: \ch{A <=>>[x][y] B} \par
- longer: \ch[arrow-offset=12pt]{A <=>>[x][y] B} \par
- higher: \ch[arrow-yshift=2pt]{A <=>>[x][y] B} \par
- more balanced: \ch[arrow-ratio=.8]{A <=>>[x][y] B} \par
- labels further away: \ch[label-offset=4pt]{A <=>>[x][y] B} \par
- larger distance to compounds: \ch[compound-sep=2ex]{A <=>>[x][y] B} \par
- smaller labels: \ch[label-style=\tiny]{A <=>[x][y] B}
-\end{example}
-
-If you want to have different arrow tips\sinceversion{4.7} there is an easy
-way to use existing arrow tips (as defined by \TikZ). \chemformula\ uses
-three different arrow tips: \code{cf}, \code{left cf} and \code{right cf}. If
-you want them to match those of \pkg{chemfig}~\cite{pkg:chemfig} for example
-you could do:
-\begin{sourcecode}
- \pgfkeys{
- cf /.tip = {CF@full} ,
- left cf /.tip = {CF@half}
- }
-\end{sourcecode}
-\pkg{chemfig} has no equivalent of \code{right cf}. This mechanism relies on
-\TikZ\ version~3.0.0 and the new \code{arrows.meta} library.
-
-\subsection{Modify Arrow Types}\label{sec:arrows_modify}
-The arrows are defined with the commands
-\begin{commands}
- \command{NewChemArrow}[\marg{type}\marg{\TikZ}]
- Define the new arrow type \meta{type}. Issue an error if an arrow type
- \meta{type} already exists.
- \command{ProvideChemArrow}[\marg{type}\marg{\TikZ}]
- Define\sinceversion{4.12a} the new arrow type \meta{type} only if it
- doesn't exist, yet.
- \command{DeclareChemArrow}[\marg{type}\marg{\TikZ}]
- Define the new arrow type \meta{type} or overwrite it if it already
- exists.
- \command{RenewChemArrow}[\marg{type}\marg{\TikZ}]
- Redefine the arrow type \meta{type}. Issue an error if an arrow type
- \meta{type} doesn't exist.
- \command{ShowChemArrow}[\marg{type}]
- Print out the current definition of the arrow type \meta{type}.
-\end{commands}
-\meta{type} is the sequence of tokens that is replaced with the actual arrow
-code. For example the basic arrow is defined via
-\begin{sourcecode}
- \NewChemArrow{->}{
- \draw[chemarrow,-cf] (cf_arrow_start) -- (cf_arrow_end) ;
- }
-\end{sourcecode}
-In order to define arrows yourself you need to know the basics of
-\TikZ\footnote{Please see the \manual{pgfmanual} for details.}. The
-predefined arrows use the arrow tips \code{cf}, \code{left cf} and \code{right
- cf}. They also all except the net reaction arrow \code{==} use the
-\TikZ-style \code{chemarrow} that you should use, too, if you want the option
-\option{arrow-style} to have an effect.
-
-There are some predefined coordinates you can and should use. For
-completeness' sake the arrow tips and the \TikZ-style are also listed:
-\begin{codedesc}
- \Code{(cf\_arrow\_start)}
- The beginning of the arrow.
- \Code{(cf\_arrow\_end)}
- The end of the arrow.
- \Code{(cf\_arrow\_mid)}
- The mid of the arrow.
- \Code{(cf\_arrow\_mid\_start)}
- The beginning of the shorter arrow in types like \verbcode+<=>>+.
- \Code{(cf\_arrow\_mid\_end)}
- The end of the shorter arrow in types like \verbcode+<=>>+.
- \Code{cf}
- A double-sided arrow tip.
- \Code{left cf}
- A left-sided arrow tip.
- \Code{right cf}
- A right-sided arrow tip.
- \Code{chemarrow}
- \chemformula's \TikZ-style that is applied to the arrows and set with
- \option{arrow-style}
-\end{codedesc}
-\begin{example}
- \NewChemArrow{.>}{
- \draw[chemarrow,-cf,dotted,red] (cf_arrow_start) -- (cf_arrow_end);
- }
- \NewChemArrow{n>}{
- \draw[chemarrow,-cf]
- (cf_arrow_start)
- .. controls ([yshift=3ex]cf_arrow_mid) ..
- (cf_arrow_end);
- }
- \ch{A .> B} \ch{A .>[a][b] B} \ch{A n> B}
-\end{example}
-
-\begin{example}
- \texttt{\ShowChemArrow{->}} \par
- \RenewChemArrow{->}{\draw[chemarrow,->,red] (cf_arrow_start) -- (cf_arrow_end) ;}
- \texttt{\ShowChemArrow{->}} \par
- \ch{A -> B}
-\end{example}
-
-\subsection{Standalone Arrows}
-\chemformula\ offers\sinceversion{4.0} a command that \emph{only accepts} the
-\enquote{arrow} input type:
-\begin{commands}
- \command{charrow}[\marg{type}\oarg{above}\oarg{below}]
- Print the arrow type \meta{type}.
-\end{commands}
-This command is internally used for the arrows, too, when \cs{ch} is parsed.
-
-\section{Names}
-\subsection{Syntax}
-\chemformula\ has a built-in syntax to write text under a compound. In a way
-it works very similar to the arrows.
-\begin{commands}
- \command{ch}[\Marg{ !(\meta{text})( \meta{formula} ) }]
- Writes \meta{text} below \meta{formula}.
-\end{commands}
-If an exclamation mark is followed by a pair of parentheses \chemformula\ will
-parse it this way:
-\begin{example}
- \ch{!(ethanol)( CH3CH2OH )}
-\end{example}
-The same what's true for the arrows arguments holds for these arguments: if
-you leave blanks the different parts will be treated according to their input
-type before the text is set below the formula.
-\begin{example}
- \ch{!(water)(H2O)} \quad
- \ch{!( "\textcolor{blue}{water}" )( H2O )} \quad
- \ch{!( $2n-1$ )( H2O )} \quad
- \ch{!( H2O )( H2O )} \quad
- \ch{!(oxonium)( H3O+ )}
-\end{example}
-If for some reason you want to insert an exclamation mark \emph{without} it
-creating a name you only have to make sure it isn't followed by parentheses.
-\begin{example}[side-by-side]
- \ch{H2O~(!)} \par
- \ch{A!{}()}
-\end{example}
-
-\subsection{Customization}
-\chemformula\ provides two options to customize the output of the names:
-\begin{options}
- \keyval{name-format}{commands}\Default{\cs*{scriptsize}\cs*{centering}}
- The format of the name. This can be arbitrary input.
- \keychoice{name-width}{\meta{dim},auto}\Default{auto}
- The width of the box where the label is put into. \code{auto} will detect
- the width of the name and set the box to this width.
-\end{options}
-\begin{example}
- \ch{!(acid)( H2SO4 ) -> B} \par
- \ch[name-format=\sffamily\small]{!(acid)( H2SO4 ) -> B} \par
- \ch[name-format=\scriptsize N:~]{!(acid)( H2SO4 ) -> B} \par
- \ch[name-width=3em,name-format=\scriptsize\raggedright]{!(acid)( H2SO4 ) -> B}
-\end{example}
-
-\subsection{Standalone Names}
-\chemformula\ offers a command\sinceversion{4.0} that allows the usage of the
-\enquote{name} syntax in normal text. This is the command that a bang is
-replaced with in \chemformula's formulas, actually. Both arguments are
-mandatory.
-\begin{commands}
- \command{chname}[\darg{text~1}\darg{text~2}]
- The command that is useed internally for placing \meta{text~1} below of
- \meta{text~2}.
-\end{commands}
-
-\section{Format and Font}\label{sec:format}
-In the standard setting \chemformula\ doesn't make any default changes to the
-font of the formula output. Let's take a look at a nonsense input which shows
-all features:
-\begin{example}[pre-output={\biolinumLF\libertineLF\setchemformula{format=}}]
- \newcommand*\sample{%
- \ch{H2C-C+C-CH=CH+ + CrO4^2-
- <=>[x][y]
- 2.5 Cl^{-.} + 3_1/2 Na*OH_{(aq)} + !(name)( A^n ) "\LaTeXe"}
- }
- \sample
-\end{example}
-\newcommand*\sample{%
- \ch{H2C-C+C-CH=CH+ + CrO4^2-
- <=>[x][y]
- 2.5 Cl^{-.} + 3_1/2 Na*OH_{(aq)} + !(name)( A^n ) "\LaTeXe"}
-}
-
-Now we're going to change different aspects of the font a look what happens:
-\begin{example}[pre-output={\biolinumLF\libertineLF\setchemformula{format=}}]
- \sffamily Hallo \sample \\
- \ttfamily Hallo \sample \normalfont \\
- \bfseries Hallo \sample \normalfont \\
- \itshape Hallo \sample
-\end{example}
-As you can see most features adapt to the surrounding font.
-
-If you want to change the default format you need to use this option:
-\begin{options}
- \keyval{format}{code}\Default
- Adds \meta{code} before the output of \cs{ch}.
- \keyval{atom-format}{code}\Default
- This\sinceversion{4.13} adds \meta{code} before each formula. This
- allows to specify a format for the chemical formulas only and have a
- different format for the rest of the chemical equation.
-\end{options}
-\begin{example}[pre-output={\biolinumLF\libertineLF\setchemformula{format=}}]
- \definecolor{newblue}{rgb}{.1,.1,.5}
- \setchemformula{format=\color{newblue}\sffamily}
- \sffamily Hallo \sample \\
- \ttfamily Hallo \sample \normalfont \\
- \bfseries Hallo \sample \normalfont \\
- \itshape Hallo \sample
-\end{example}
-
-You can also specifically change the fontfamily, fontseries and fontshape of
-the output.
-\begin{options}
- \keyval{font-family}{family}\Default
- Changes the fontfamily of the output with \cs*{fontfamily}\marg{family}.
- \keyval{font-series}{series}\Default
- Changes the fontseries of the output with \cs*{fontseries}\marg{series}.
- \keyval{font-shape}{shape}\Default
- Changes the fontshape of the output with \cs*{fontshape}\marg{shape}.
-\end{options}
-\begin{example}[pre-output={\biolinumLF\libertineLF\setchemformula{format=}}]
- \setchemformula{font-series=bx}
- Hallo \sample \par
- \sffamily Hallo \sample \normalfont \par
- \setchemformula{font-family=lmss,font-series=m} Hallo \sample
- \normalfont \par
- \itshape Hallo \sample
-\end{example}
-
-If you're using \XeLaTeX\ or \LuaLaTeX\ and have loaded \pkg{fontspec} you
-have the possibilty to set the font with it:
-\begin{options}
- \keyval{font-spec}{font}\Default
- Use font \meta{font} for \chemformula's formulas.
-\end{options}
-or with options
-\begin{options}
- \keychoice{font-spec}{\Marg{[\meta{options}]\meta{font}}}
- Use font \meta{font} with options \meta{options} for \chemformula's
- formulas.
-\end{options}
-Since this document is typeset with \pdfLaTeX\ the option cannot be
-demonstrated here.
-
-\section{Usage In Math Equations}
-The \cs{ch} command can be used inside math equations. It recognizes
-\verbcode+\\+ and \verbcode+&+ and passes them on. However, you can't use the
-optional arguments of \verbcode+\\+ inside \cs{ch}.
-\begin{example}
- \begin{align}
- \ch{
- H2O & ->[a] H2SO4 \\
- Cl2 & ->[x][y] CH4
- }
- \end{align}
- \begin{align*}
- \ch{
- RNO2 &<=>[ + e- ] RNO2^{-.} \\
- RNO2^{-.} &<=>[ + e- ] RNO2^2-
- }
- \end{align*}
-\end{example}
-
-\section{Usage with \TikZ\ or \pkg*{pgfplots} and externalization}
-Since \chemformula\ uses\sinceversion{4.1} \TikZ\ to draw reaction arrows
-and bonds they would be externalized, too, if you use that facility with
-\TikZ\ or \needpackage{pgfplots}~\cite{pkg:pgfplots}. This may not be
-desirable since they are very small pictures maybe containing of a single
-line. This is why \chemformula's default behaviour is to disable
-externalization for it's bonds and arrows. This can be turned on and off
-through the following option:
-\begin{options}
- \keybool{tikz-external-disable}\Default{true}
- dis- or enable \TikZ' externalization mechanism for \chemformula's arrows
- and bonds.
-\end{options}
-
-If you should be using a formula that contains bonds or arrows inside of a
-\code{tikzpicture} that is externalized you should locally enable it for
-\chemformula, too:
-
-\begin{sourcecode}
- \begin{tikzpicture}
- \setchemformula{tikz-external-disable=false}
- \begin{axis}[xlabel={\ch{2 H+ + 2 e- -> H2}}]
- \addplot ... ;
- \end{axis}
- \end{tikzpicture}
-\end{sourcecode}
-
-\section{Lewis Formulae}\label{sec:lewis-formulae}
-\chemformula\ offers\sinceversion{4.2} a command to typeset Lewis formulae.
-This does not mean Lewis structures! Those can be achieved using the
-\pkg{chemfig} package~\cite{pkg:chemfig}. \chemformula\ provides the
-possibility to draw electrons as dots and pairs of dots or a line around an
-atom.
-
-\begin{commands}
- \command{chlewis}[\oarg{options}\marg{electron spec}\marg{atom}]
- Draws electrons around the \meta{atom} according to \meta{electron spec}.
-\end{commands}
-
-Electrons are specified by the angle to the horizontal in the couter-clockwise
-direction. The default appearance is a pair of electrons drawn as a pair of
-dots. Other specifications can be chosen. The specification follows the
-pattern \meta{angle}\meta{separator}. \meta{angle} is a positiv or negativ
-integer denoting the angle counter clockwise to the horizontal where the
-electrons should be drawn. \meta{separator} is either a dot (\code{.}, single
-electron), a colon (\code{:}, electron pair), a vertical line (\code{|},
-electron pair), an o (\code{o}, empty pair), or a comma (\code{,} default
-spec).
-
-\begin{commands}
- \command{chlewis}[\Marg{\meta{angle1}\meta{type1}\meta{angle2}\meta{type2}}%
- \marg{atom}]
- For example: \cs{chlewis}\Marg{0,180}\Marg{O} gives \chlewis{0,180}{O} and
- \cs{chlewis}\Marg{0.90.180.270.}\Marg{C} gives
- \chlewis{0.90.180.270.}{C}.
-\end{commands}
-
-The appearance can be influenced by a number of options:
-\begin{options}
- \keychoice{lewis-default}{.,:,|,o,single,pair,pair (dotted),pair
- (line),empty}\Default{pair}
- Sets the default type that is used when no type is given in \meta{electron
- spec}.
- \keyval{lewis-distance}{dim}\Default{1ex}
- The distance of two electrons in a pair.
- \keyval{lewis-line-length}{dim}\Default{1.5ex}
- The length of the line representing an electron pair.
- \keyval{lewis-line-width}{dim}\Default{1pt}
- The thickness of a line representing an electron pair.
- \keyval{lewis-offset}{dim}\Default{.5ex}
- The distance of the symbols from the atom.
-\end{options}
-The dots are drawn according to the \option{radical-radius} option mentioned
-in section~\ref{ssec:compounds:customization}.
-
-The basic usage should be more or less self-explaining:
-\begin{example}[side-by-side]
- \chlewis{0:90|180.270}{O}
- \quad
- \chlewis{45,135}{O}
- \quad
- \chlewis{0o}{Na}
-\end{example}
-
-The next example shows the effect of some of the options:
-\begin{example}
- \chlewis[lewis-default=.]{23,68,113,158,203,248,293,338}{X}
- \quad
- \chlewis{0,90,180,270}{X}
- \quad
- \chlewis[lewis-distance=1.25ex]{0,90,180,270}{X}
- \quad
- \chlewis[lewis-distance=.75ex,radical-radius=.5pt]{0,90,180,270}{X}
- \quad
- \chlewis[
- radical-radius=.5pt,
- lewis-default=.
- ]{23,68,113,158,203,248,293,338}{X}
-\end{example}
-
-\begin{example}
- \ch{
- !($1s^22s^1$)( "\chlewis{180.}{Li}" ) +
- !($1s^22s^22p^5$)( "\chlewis{0.90,180,270}{F}" )
- ->
- !($1s^2$)( Li+ ) + !($1s^22s^22p^6$)( "\chlewis{0,90,180,270}{F}" {}- )
- }
-\end{example}
-
-\section{Kröger-Vink Notation}\label{sec:kroger-vink-notation}
-
-\chemformula\ also supports the Kröger-Vink notation\sinceversion{4.5}.
-\begin{options}
- \keybool{kroeger-vink}\Default{false}
- Enable the Kröger-Vink notation. As most options this can be enabled
- globally via the setup command or locally as option to \cs{ch}.
-\end{options}
-
-With this option enabled several changes come into effect: \verbcode|'|
-produces a prime, a \code{x} in a superscript produces $\times$, and both a
-\code{.} and a \code{*} produce a little filled circle. In the Kröger-Vink
-notation a prime denotes a negative relative charge, the circle a positive
-relative charge, and the cross denotes a neutral relative charge.
-
-\begin{example}[side-by-side,add-sourcecode-options={literate=}]
- \setchemformula{kroeger-vink=true}
- \ch{Al_{Al}^'}
- \ch{Al_{Al}'}\par
- \ch{Ni_{Cu}^{x}}\par
- \ch{V_{Cl}^.}
- \ch{V_{Cl}^*}\par
- \ch{Ca_i^{..}}\par
- \ch{e^'}\par
- \ch{Cl_i^'}
- \ch{Cl_i'}\par
- \ch{O_i^{''}}
- \ch{O_i''}
-\end{example}
-
-There are a number of options for customizations:
-\begin{options}
- \keyval{kv-positive-style}{\TikZ}\Default
- \TikZ\ code for positive charge dot.
- \keyval{kv-positive-radius}{dim}\Default{.3ex}
- Radius of positive charge dot
- \keyval{kv-positive-hshift}{dim}\Default{.15em}
- Horizontal shift of positive charge dot
- \keyval{kv-positive-vshift}{dim}\Default{.5ex}
- Vertical shift positive charge dot
- \keyval{kv-positive-offset}{dim}\Default{.4em}
- The offset of two consecutive positive charge dots
- \keyval{kv-neutral-symbol}{\TeX\ code}\Default{\$\cs*{times}\$}
- Symbol for neutral particles.
-\end{options}
-
-
-
-% \section{Further Examples}
-% This section presents some examples of a possible usage.
-
-% \begin{example}
-% \begin{reaction}[Synthese von Alkanen]
-% !(Synthesegas)( $n$ CO + $(2n+1)$ H2 )
-% ->[\SI{200}{\celsius}][[CoNi]]
-% C_{$n$}H_{$2n+2$} + $n$ H2O
-% \end{reaction}
-% \end{example}
-
-% \begin{example}
-% \begin{reactions*}
-% "a)" && CH4 + Cl2 &-> CH3Cl + HCl && "{\small Chlormethan/Methylchlorid}" \\
-% "b)" && CH3Cl + Cl2 &-> CH2Cl2 + HCl && "{\small Dichlormethan/Methylenchlorid}" \\
-% "c)" && CH2Cl2 + Cl2 &-> CHCl3 + HCl && "{\small Trichlormethan/Chloroform}" \\
-% "d)" && CHCl3 + Cl2 &-> CCl4 + HCl && "{\small Tetrachlormethan/Tetrachlorkohlenstoff}"
-% \end{reactions*}
-% \end{example}
-
-% \begin{example}
-% \chemsetup[ox]{parse=false}
-% \ch{
-% "\ox{\delm,C}" -{} "\ox{\delp,M}" \qquad
-% ( <-> "\ox{\delp,C}" -{} "\ox{\delm,Br}" )
-% } \\
-% \ch[adduct-space=0pt]{X. + .Y <=> X-Y + Bindungsenergie} \\
-% \ch[name-format=\normalsize]{
-% !(\State{H}{f}\qquad)() !(\textcolor{red}{??})( CH4\gas{} ) +
-% !(\num{0})( 2 O2\gas{} )
-% ->
-% !(\num{-94.3})( CO2\gas{} ) +
-% !(\num{-57.9})( H2O\lqd{} ) +
-% !(\num{-192.1})( "\State{H}" )
-% }
-% \end{example}
-
-% \begin{example}
-% \newcommand\cstack[1]{%
-% \clap{%
-% \begin{tabular}{c}
-% #1
-% \end{tabular}
-% }%
-% }
-% \begin{reactions*}
-% CH3MgBr + "\ox*{1,Cu}" X &
-% -> "\glqq" CH3 "\ox*{1,Cu}\grqq" + MgBrX "\qquad X~$=$~Br,I,CN" \\
-% 2 MeLi + CuI &
-% -> !(\cstack{Dimethylcuprat\\(Gilmann-Cuprat)})( Me2CuLi ) + Li
-% \end{reactions*}
-% \end{example}
-
-% \begin{example}
-% % needs `chemfig'
-% \begin{reactions*}
-% H3C-CH3 + Cl2 &
-% ->[$\Delta$][$h\nu$] H3CCH2Cl + HCl & &
-% "\Enthalpy{-27.1}" \\
-% H3C-CH3 + "\Lewis{0.,Cl}" &
-% -> H3CCH2 "\Lewis{0.,\vphantom{H}}" + HCl & &
-% "\Enthalpy{-5.0}" \\
-% H3C-CH2 "\Lewis{0.,\vphantom{H}}" + Cl2 &
-% -> H3CCH2Cl + "\Lewis{0.,Cl}" & &
-% "\Enthalpy{-23.0}"
-% \end{reactions*}
-% \end{example}
-
-% The following example shows how the cancelling of compounds could be
-% done\footnote{Inspired by a question on TeX.SE:
-% \url{http://tex.stackexchange.com/q/30118/5049}}.
-% \begin{example}
-% % needs `cancel'
-% \begin{align*}
-% \ch{\cancel{HCOOH\aq} + H2O\lqd{} &<=> H3O^+\aq{} + \cancel{HCOO^-\aq}} \\
-% \ch{\cancel{HCOO^-\aq} + H2O\lqd{} &<=> \cancel{HCOOH\aq} + OH^-\aq}\\[-1ex]
-% \cline{1-2}
-% \ch{H2O\lqd{} + H2O\lqd{} &<=> H3O^+\aq{} + OH^-\aq}
-% \end{align*}
-% \end{example}
-
-\appendix
-\newenvironment{changes}[2][]{%
- \subsection*{Version #2\ifblank{#1}{}{ (#1)}}
- \itemize\let\change\item
-}{\enditemize}
-
-\section{History Since Version~4.0}
-
-\begin{changes}{4.0}
- \change Since version 4.0\sinceversion{4.0}, the \chemformula\ package is
- distributed independently from \chemmacros.
-\end{changes}
-
-\begin{changes}{4.1}
- \change New option \option{tikz-external-disable}.
- \change New option \option{frac-math-cmd}.
-\end{changes}
-
-\begin{changes}{4.2}
- \change New option \option{arrow-style}.
- \change New command \cs{chlewis} that allows to add Lewis electrons to an
- atom, see section~\ref{sec:lewis-formulae}.
-\end{changes}
-
-\begin{changes}{4.3}
- \change New option \option{stoich-print}.
- \change New command \cs{chstoich}.
- \change The commands \cs*{DeclareChem\meta{...}} now don't give an error any
- more if the command already exists. This is more consistent with \LaTeX's
- \cs*{DeclareRobustCommand}. For all those commands a version
- \cs*{NewChem\meta{...}} is introduced that \emph{does} give an error if
- the new command is already defined.
-\end{changes}
-
-\begin{changes}{4.4}
- \change A single dash \code{-} in \cs{ch} is now treated as a minus sign.
- This is consistent with the behaviour of a \code{+}.
-\end{changes}
-
-\begin{changes}{4.5}
- \change New arrow types \arrowtype{>=<}, \arrowtype{>=<{}<}, \arrowtype{>{}>=<}
- and \arrowtype{<==>}.
- \change Internal changes to \cs{ch} allow usage of optional arguments of
- \cs*{\textbackslash} and \cs*{label} in \chemmacros' \env*{reactions}
- environment.
-\end{changes}
-
-\begin{changes}{4.6}
- \change New options \option{circled} and \option{circletype}. this allows to
- set the behaviour as described on \chemmacros' manual for a specific usage
- of \cs{ch}.
-\end{changes}
-
-\begin{changes}{4.7}
- \change Dependency change: \chemformula\ now requires the \TikZ\ library
- \code{arrows.meta} instead of the library \code{arrows}. This requires
- \TikZ\ version~3.0.0.
-\end{changes}
-
-\begin{changes}{4.8}
- \change The \chemformula\ package now is no longer part of the \chemmacros\
- bundle but is distributed as a package of it's own.
-\end{changes}
-
-\begin{changes}{4.9}
- \change New options \option{minus-space} and \option{minus-penalty} equivalent
- to the existing \option{plus-space} and \option{plus-penalty}
- \change New options \option{plus-output-symbol} and
- \option{minus-output-symbol} for customizing the plus and minus signs in
- the output.
-\end{changes}
-
-\begin{changes}{4.10}
- \change New macro set \cs{NewChemCompoundProperty}, see
- section~\ref{sec:extend-comp-prop} for a description.
-\end{changes}
-
-\begin{changes}{4.11}
- \change New macro set \cs{NewChemAdditionSymbol}, see
- section~\ref{sec:addition-symbols}.
- \change New macro set \cs{NewChemSymbol}, see section~\ref{sec:symbols}.
-\end{changes}
-
-\begin{changes}{4.12}
- \change Change package requirement: \chemformula\ now not loads complete
- \pkg{amsmath} but only \pkg{amstext}.
-\end{changes}
-
-\begin{changes}{4.13}
- \change Check for blank input parts and don't process them.
- \change Drop support for \cs*{[} and \cs*{]} as replacement for \code{[} and
- \code{]} inside arrow captions.
- \change New option \option{atom-format}.
-\end{changes}
-
-\begin{changes}{4.14}
- \change New option \option{adduct-penalty}.
-\end{changes}
-
-\end{document}