# Bold Greek letters in achemso

I'm having trouble producing a bold capital "Pi" while using the achemso document class. The only success that I've had is by using \bm{\Pi} which produces an ugly result akin to "poor man's bold", \pmb. I think I've narrowed it down to achemso's use of mathptmx that causes this problem. Here's a minimal example that illustrates the problem:

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{mathptmx}
\usepackage{bm}
\title{Title}
\author{Author}
\begin{document}
\maketitle
$$\begin{split} &\text{normal: } \Pi \\ &\text{mathbf: } \mathbf{\Pi} \\ &\text{bm: } \bm{\Pi} \end{split}$$
\end{document}


Is there any way of producing a clean-looking bold capital "Pi" that will be compatible with achemso and pdfLaTeX?

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With mathptmx there is no boldface math. –  egreg Feb 5 '13 at 22:49
@egreg -- Are you sure about this claim? If one types \boldsymbol{\Pi} rather than \mathbf{\Pi} in the MWE above, LaTeX has no problem generating a nice bold \Pi symbol. –  Mico Feb 6 '13 at 1:27
@Mico That was a general comment; in the particular case it seems that achemso is doing some nasty things, because \Pi is taken from the Symbol font that can be emboldened. –  egreg Feb 6 '13 at 9:31
You get a correct bold \Pi if bm is loaded with \RequirePackage before \documentclass{achemso}. I've asked the class maintainer what he thinks. –  egreg Feb 6 '13 at 9:36
@egreg I can confirm that, as you suggest, using \RequirePackage{bm} before the \documentclass{achemso} does produce a bold Pi. Oddly, it appears to change the font slightly. The bold Pi appears with "flat" serifs where as the normal font has "tapered" serifs. You can see these two different Pi symbols in the image posted by @Boris, mathbf vs bm. –  tarheels Feb 6 '13 at 18:03

## 1 Answer

Mathptmx is an older package, which lacks many features provided by newer Times-compatible font packages. Newtxtext and newtxmath are a very good alternative.

Try this:

\documentclass[12pt]{article}
\usepackage{amsmath,achemso}
\usepackage{newtxmath}
\usepackage{newtxtext}
\usepackage{bm}
\title{Title}
\author{Author}
\begin{document}
\maketitle
$$\begin{split} &\text{normal: } \Pi \\ &\text{mathbf: } \mathbf{\Pi} \\ &\text{bm: } \bm{\Pi} \end{split}$$
\end{document}


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Wow, that works great! Does anyone know if this fix is OK for ACS journal submission? –  tarheels Feb 5 '13 at 23:58
mathptmx is indeed an older package, but a lack of bold math symbols is not one of its shortcomings. If one types \boldsymbol{\Pi} instead of \mathbf{\Pi}, there is no problem. –  Mico Feb 6 '13 at 1:29
@tarheels You can always upload a PDF. I don't have access to the full detail of the TeX system installed on the ACS servers, so the only way to find out if it will work there with newtxmath is to submit and see! –  Joseph Wright Feb 6 '13 at 9:54
@Micro I tried \boldsymbol{\Pi}. When using amsmath only, \boldsymbol{\Pi} yields the same result as \Pi. When using amsmath and bm, \boldsymbol{\Pi} yields the same result as \bm{\Pi} (which is a "poor man's bold"). If there's something I'm missing that's causing this issue, I'd be glad to try it. –  tarheels Feb 6 '13 at 17:12
@JosephWright Thanks, I think I'll just have to see what happens at submission. Not being able to produce a bold greek letter is quite a drawback, especially when trying to stay consistent with previous work, so I don't think I have much of a choice. –  tarheels Feb 6 '13 at 17:17