Hello Henrique Junior,
You haven't provided any information about your example, but I am guessing you are using the chemstyle package (from the
\ce
commands). You might want to look
here for providing a
minimal working example.
I am not sure how to get the undersets with chemstyle, I prefer the chemmacros package instead, which I think is much more powerful.
Here is your example using chemmacros:
Code: Select all
\documentclass{article}
\usepackage{chemmacros}
\begin{document}
\ch{Cu^{2+} + 4 NH3 <=> [Cu(NH3)4]^2+}
\end{document}
And here is the code that produces undersets:
Code: Select all
\documentclass{article}
\usepackage{chemmacros}
\begin{document}
\ch{!(under1\linebreak under2)( Cu^{2+} ) + !(under3\linebreak under4)( 4 NH3 ) <=> !(under5\linebreak under6)( [Cu(NH3)4]^{2+} )}
\end{document}
As you can see, most compunds written in chemstyle syntax can be simply converted to chemmacros syntax by changing
\ce
to
\ch
, however there are several differences between the two. In fact I think chemmacros syntax is actually simpler. I hope this helps in your case.
Edit: It seems you might be using the mhchem package which allows you to use the
\underset
command by entering math mode. Loot at
this post for a solution if you want to stick with mhchem. However I would still prefer chemmacros, because when you enter mathmode you will have to keep using
\mathrm{}
to avoid italicizing all the text.