[OS X TeX] Conflict between mtpro2 and mhchem

[Michael Sharpe]

> On Mar 11, 2017, at 10:34 AM, Themis Matsoukas <tmatsoukas at icloud.com> wrote:
> 
> This may be a known issue but I encountered it just recently. In TeX Live 2016 there is a conflict between the packages mhchem and mtpro2. The sample file below upon compilation gives the error message:
> 
> /Users/themis/Library/texmf/tex/latex/mtpro2/mtpro2.sty:131: No room for a new 
> \count .
> \ch at ck ...\else \errmessage {No room for a new #3}
>                                                  \fi 
> l.131 \alloc at 0\count\countdef\insc at unt\pointcount@
> 
> The conflict disappears if mhchem is loaded after mtpro2. 
> 
> %-------------------------------------------------------------
> \documentclass{memoir}
> \renewcommand{\rmdefault}{ptm} 
> \usepackage[version=4]{mhchem}
> \usepackage[lite,subscriptcorrection,nofontinfo]{mtpro2}
> 
> \begin{document}
> 
> Testing conflict between \texttt{mhchem} and \texttt{mtpro2}: 
> 
> \begin{equation*}
>   \ce{(NH4)2S} 
> \end{equation*}
> 
> \end{document} 
> %-------------------------------------------------------------
> 

The error will go away if you  place the line

\usepackage{etex}

before loading mhchem.

Miichael