Beamer reactions numbering issue

Question

Using the reactions environment in Beamer along with \begin{itemize}[<+->] causes the reactions to be renumbered when uncovering. In the following example the reactions are labelled 1-3 on the intial slide as required, but on uncovering the text in the list they are subsequently renumbered 4-5, 7-9, 10-12 and 13-15. Is there a quick fix to this without removing the [<+->] of \begin{itemize}[<+->] ;)

I tried putting \numberwithin{reaction}{chapter} frame and slide in place of chapter as suggested by this Chemmacros is not resetting the reactions counter in the new chapter. I guess I need to replace chapter by the correct counter identifier...

\documentclass{beamer}
\usepackage{chemfig}
\usepackage{chemmacros}
\begin{document}
\chemsetup[chemformula]{font-shape=sf}
\begin{frame}
\begin{reactions}
 Cl-Cl ->[$\Delta$][$h\nu$] 2 "\Lewis{0.,Cl}"  \label{react:init}\\
R3H + Cl "\Lewis{0.,\vphantom{H}}" -> R3 "\Lewis{0.,\vphantom{H}}" + HCl    \label{react:propagation}
\end{reactions}
\begin{itemize}[<+->]
\item Initiation is cleavage of \ch{Cl-Cl} bond, Reaction~\ref{react:init}
\item 1st reaction is that of \ch{ Cl "\Lewis{0.,\vphantom{H}}"} with a hydrogen, Reaction~\ref{react:propagation1}
\item Once the carbon radical is formed \ch{ R3 "\Lewis{0.,\vphantom{H}}" }, subsequent bonding to the halogen \ch{Cl-Cl} can only occur at the radical site, Reaction~\ref{react:prop2}
\item Formation of \ch{HCl} is common to all reactants so determining factor must be the dissociation of the \ch{R-H} bond
\item Therefore not all \ch{C-H} bonds are equal
\end{itemize}
\end{frame}
\end{document}

score 2 · Accepted Answer · answered Feb 10 '14 at 13:55

You need

\resetcounteronoverlays{reaction}

to prevent the counter from stepping when using overlay specifications.

\documentclass{beamer}
\usepackage{chemfig}
\usepackage{chemmacros}

\resetcounteronoverlays{reaction}

\begin{document}
\chemsetup[chemformula]{font-shape=sf}
\begin{frame}
\begin{reactions}
 Cl-Cl ->[$\Delta$][$h\nu$] 2 "\Lewis{0.,Cl}"  \label{react:init}\\
R3H + Cl "\Lewis{0.,\vphantom{H}}" -> R3 "\Lewis{0.,\vphantom{H}}" + HCl    \label{react:propagation}
\end{reactions}
\begin{itemize}[<+->]
\item Initiation is cleavage of \ch{Cl-Cl} bond, Reaction~\ref{react:init}
\item 1st reaction is that of \ch{ Cl "\Lewis{0.,\vphantom{H}}"} with a hydrogen, Reaction~\ref{react:propagation1}
\item Once the carbon radical is formed \ch{ R3 "\Lewis{0.,\vphantom{H}}" }, subsequent bonding to the halogen \ch{Cl-Cl} can only occur at the radical site, Reaction~\ref{react:prop2}
\item Formation of \ch{HCl} is common to all reactants so determining factor must be the dissociation of the \ch{R-H} bond
\item Therefore not all \ch{C-H} bonds are equal
\end{itemize}
\end{frame}
\end{document}

enter image description here

Beamer reactions numbering issue

1 Answers1