# LaTeX problem: The \rightleftarrows symbol is too short

The \rightleftarrows symbol is too short horizontally for my liking. My search engine finds no helpful results for "latex longrightleftarrows". Is there some way to extend the symbol horizontally?

\documentclass[12pt,letterpaper]{article}
\usepackage[utopia]{mathdesign}
\usepackage{amsmath}
\usepackage{mhchem}
\usepackage{gensymb}
...
\begin{document}
\ce{\rightleftarrows}
\end{document}

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Welcome to TeX.SX! A tip: You can use backticks  to mark your inline code as I did in my edit. –  Adam Liter Apr 7 '14 at 2:04
This answer might be helpful: tex.stackexchange.com/a/91524/32888 –  Adam Liter Apr 7 '14 at 2:08
Thanks, Adam. Harish's edit at that link is the output closest to what I'm looking for. –  LaTeX2enub1336 Apr 7 '14 at 3:07

If you are happy with harpoons, you can use xleftrightharpoons from mathtools

\documentclass[12pt,letterpaper]{article}
\usepackage[utopia]{mathdesign}
\usepackage{mathtools}
\usepackage{mhchem}
\usepackage{gensymb}

\begin{document}

\ce{A\rightleftarrows B}

\ce{A\xleftrightharpoons{\rule{2cm}{0pt}} B}

\ce{A\xleftrightharpoons{\hphantom{\hspace*{1cm}}} B}

\end{document}


\documentclass[12pt,letterpaper]{article}
\usepackage[utopia]{mathdesign}
\usepackage{mathtools}
\usepackage{mhchem}
\usepackage{gensymb}

\begin{document}

\ce{A\rightleftarrows B}

\ce{A\xleftrightharpoons{\text{my reaction}} B}

\end{document}


Another variant:

\documentclass[12pt,letterpaper]{article}
\usepackage[utopia]{mathdesign}
\usepackage{mathtools}
\usepackage{mhchem}
\usepackage{gensymb}
\newcommand{\myrightleftarrows}[1]{\mathrel{\substack{\xrightarrow{#1} \\[-.9ex] \xleftarrow{#1}}}}

\begin{document}

\ce{A\rightleftarrows B}

\ce{A\myrightleftarrows{\rule{2cm}{0cm}} B}    %%% change 2cm as you wish
\end{document}


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That's exactly what I had in mind. Thank you, Harish. –  LaTeX2enub1336 Apr 7 '14 at 5:03

If you are willing to use chemfig you can easily control the arrow attributes:

\documentclass[12pt,letterpaper]{article}
\usepackage[utopia]{mathdesign}
\usepackage{amsmath}
\usepackage{mhchem}
\usepackage{gensymb}
\usepackage{chemfig}

\begin{document}

\ce{A\rightleftarrows B}

\schemestart
A\arrow{<=>}B
\schemestop

\setarrowdefault{0,0.7,red,thick}
\schemestart
A\arrow{<=>}B
\schemestop

\end{document}
`

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I was really hoping for two arrows. Nevertheless, formatting arrows through chemfig is a revelation to me, so thanks for that. I think I'll go with Harish's "hack" linked to by Adam above. –  LaTeX2enub1336 Apr 7 '14 at 3:11