# chemical reactions

I would like to reproduce the same as this picture using the chemfig package:

\documentclass[french,12pt,oneside,openright]{memoir}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[a4paper]{geometry}
\usepackage[french]{babel} %langue francaise
\usepackage{graphicx,xcolor} %insertion d'images
\usepackage{titlesec}
\graphicspath{{Annexes/images/}} %directory of the images
\usepackage{lipsum} %paragraphes prédéfinis
%\usepackage{fancyhdr} %decoration des en tetes
\usepackage[sonny]{fncychap}
\usepackage{usnomencl}%pour la nomenclature
\usepackage{pgfplots}
\usepackage{chemmacros}
\usepackage{chemfig}
\renewcommand*\printatom[1]{\ensuremath{\mathsf{#1}}}

\begin{document}
\setchemrel{1pt}{}{6em}
\textbf{Sc\chemrel[\footnotesize hnu]{<->}e$^{-}_{CB}$ \chemsign+ h$^{+}_{VB}$}\\
\setchemrel{1pt}{}{6em}
\textbf{A$_{ads}$\chemsign+ e$^{-}_{CB}$ \chemrel[\footnotesize hnu]{->}A$^{{•}-}_{ads}$}\\

\end{document}

• Is there a special reason why you want to use chemfig for this? Both mhchem and chemformula (which you implicitly load through chemmacros) are much better suited for those kind of reactions... – cgnieder May 10 '15 at 18:46
• As a note; This would be trivial to create with [chemmacros](https://www.ctan.org/pkg/chemmacros?lang=en) and [chemformula](https://www.ctan.org/pkg/chemformula) – Canageek May 10 '15 at 18:46
• @clemens can you guide me a little more? if you can just help me for the first line. Thank you – Hamza.w May 10 '15 at 20:14
• I will post an answer in a bit. Out of curiosity: what does h in the reaction stand for? – cgnieder May 10 '15 at 20:24
• h for holes of the valence electron – Hamza.w May 10 '15 at 20:34

I'm not sure why you want to typeset the reactions with chemfig. It is an excellent package for drawing skeletal formulae of organic compounds. However, the reactions in your example are much easier typeset with mhchem or chemformula. The latter is loaded by chemmacros so you already have it available.

\documentclass{memoir}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}

\usepackage{chemformula}

\begin{document}

\begin{center}
\setchemformula{charge-hshift=0pt}
% \sffamily % uncomment if you want or need the following to be sans serif
\ch{ Sc ->[$h\nu$] e_{CB}- + h_{VB}+} \\[1ex]
\end{center}

\end{document}


Anyway, if you insist on using chemfig you should read what it writes in the log file and follow the advice:

Package chemfig Warning: the macro \chemrel is deprecated. Please, build schemes with \schemestart and inside, use \arrow.

\documentclass{memoir}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}

\usepackage{chemfig}
\usepackage{amsmath}% for \text

\begin{document}

\begin{center}
\schemestart
Sc
\arrow{->[$h\nu$]}
$\mathrm{e}_{\text{CB}}^- + \mathrm{h}_{\text{VB}}^+$
\schemestop\\[1ex]
\schemestart
$\mathrm{A}_{\text{ads}} + \mathrm{e}_{\text{CB}}^-$
\arrow
$\mathrm{A}_{\text{ads}}^{*-}$
\schemestop\\[1ex]
\schemestart
$\mathrm{D}_{\text{ads}} + \mathrm{h}_{\text{VB}}^+$
\arrow
$\mathrm{D}_{\text{ads}}^{*+}$
\schemestop
\end{center}

\end{document}


Using sans serif font for the reactions is possible and for the chemformula version only requires to set the surrounding text font to sans serif. In the chemfig version it requires a little bit more work.

• thanks a lot, that's what i was looking for BUT :) that "star" * should be a point, everything is nice except that dot (the dot means a free electron) thanks @clemens – Hamza.w May 10 '15 at 22:17
• Please have a look at the chemformula package's manual and especially the section about Kroeger-Vink notation. – cgnieder May 10 '15 at 22:20