# How to put a positive sign with thermodynamics module

I want to put a positive sign "+" in front of a positive number with units in thermodynamics module of chemmacros. So I made the following LaTeX cord related to this with tuning siunitx:

\usepackage{chemmacros}
\chemsetup{modules={reactions}}
\usechemmodule{thermodynamics}
\NewChemState\ElPot{ symbol=E, subscript-pos=right, superscript=\standardstate, unit=\volt}
\usepackage{siunitx}
\sisetup{retain-explicit-plus}


Then I get as \ElPot{+1.23}: "+1.23 V", and \ElPot{-1.23}: "-1.23 V".
Do you know any better method to add a positive sign within thermodynamics module?

My sample is as below:

\documentclass{article}
\usepackage{upgreek}
\usepackage{chemmacros}
\chemsetup{modules={reactions}}
\usechemmodule{thermodynamics}
\NewChemState
\ElPot{symbol=E, subscript-pos=right, superscript=\standardstate, unit=\volt}
\usepackage{siunitx}
\sisetup{retain-explicit-plus}
\begin{document}
This is a test reaction:
\begin{reactions}
H2 + 1/2 O2 <-> H2O \qquad  {} "\ElPot[pre=]{+1.23}"
\end{reactions}
\end{document}

• (1) Welcome, (2) you'll make it a lot easier for others to help if you provide a full, but minimal, example instead of sniplets like this. Then others can copy your code, and test it as is. That is a lot easier than having to guess a documentclass, preamble and document sample body. – daleif May 20 at 12:41

Is this what you are looking for?

\documentclass{article}
\usepackage{siunitx}
\begin{document}
\begin{itemize}
\item \SI{+30.0}{\volt}. No explicit + symbol
\item \SI[retain-explicit-plus=true]{+30.0}{\volt}. Explicit + symbol
\end{itemize}
\end{document}


• Thanks for your comment. Tuning siunitx is in need with/without chemmacros. – attic75 May 22 at 11:54
• @attic75 Thanks for the feedback. I'm not really sure what you are asking in your question. For example, what are you trying to simplify? Is there an approach that you are trying to use that does not work? – pdanese May 22 at 14:17
• I thought that chemmacros or thermodynamics module might have some option to put a positive sign in front of free energy or voltage, but I was not able to find. So I use an option of siunitx in my sample, which I was not sure whether it is better. I'd like to simplify my approach if possible without sinuitx... – attic75 May 23 at 10:55
• @attic75 Yeah, I don't see anything either. The only thing I can suggest is that you don't need the line "\usepackage{siunitx}" because the thermodynamics module calls siunitx. The example given in chemmacros uses the line that you already use ("\sisetup{retain-explicit-plus}"), so I think you are currently employing the appropriate example. – pdanese May 23 at 18:34
• Thanks. With your comment, I can remove one more line. – attic75 May 24 at 11:25