# Trouble with commas in subscript of chemical formula (using mhchem)

I'm writing a thesis on clay materials which have rather unusual chemical formulas with commas in the subscript. For intance I try to write the following chemical formula in LaTeX:

\begin{document}
\usepackage[version=3]{mhchem}

The chemical formula of beidelite is: \ce{Na0,5Al2(Si3,5Al0,5)O10(OH)2.n(H2O)}

\end{document}


It ignores the commas and gives the following output:

To be clear, I want the subscript after Na to say 0,5, the subscript after Si say 3,5 and the subscript after Al say 0,5.

How do i fix this?

Place the non-integers inside curly bracket groups:

\documentclass[border=5pt]{standalone}
\usepackage[version=3]{mhchem}
\begin{document}

The chemical formula of beidelite is: \ce{Na_{0,5}Al2(Si_{3,5}Al_{0,5})O10(OH)2.$n$(H2O)}

\end{document}


• You should always specify the version when loading mhchem. in this case, using the original code when specifying version=4 the commas appear in the text but as normal text not subscripts. – ArTourter Feb 6 '16 at 13:46
• I am using mhchem version 3. Should I add it to the code of my question? – Emily Feb 6 '16 at 14:07
• @Emily In general such information is useful, as answers may depend on the version of packages used. – sodd Feb 6 '16 at 14:09
• @ArTourter I'm aware, but in this case I decided to leave it out, since the version was not specified by the OP. Also, the solution is version-independent – the only difference is some different spacing in the output. But I agree that one should include the version option in general. – sodd Feb 6 '16 at 14:18
• @hooy You should replace n with $n$ as this is a variable standing for a number – and therefore should be italic. – mhchem Feb 6 '16 at 16:53