# Chemical equation in LaTeX

I am trying to create an equation in LaTeX using the following code.

\delta{$^{66}$}Zn = \Bigg[ \frac{{($^{66}$Zn/ $^{64}$Zn)$_{sample}$}}{{( $^{66}$Zn/ $^{64}$Zn)$_{standard}$}} - 1 \Bigg] \times $1000\textperthousand$


When I run TeXWorks, I end up with a bunch of errors. The errors look like

! Missing $inserted. <inserted text>$
l.11 \delta
{$^{66}$}Zn = \Bigg[ \frac{{($^{66}$Zn/ $^{64}$Zn)$_{sample}$}}{{...


I am trying to reproduced the following figure with the permille symbol at the end of the equation. The \frac command does not seem to split the numerator and the denominator as shown in the figure.

Any help will be truly appreciated. Thanks.

Here is a MWE

\documentclass{article}
\usepackage{amsmath}
\usepackage{newtxtext,newtxmath,amsmath}
\begin{document}

\delta{$^{66}$}Zn = \Bigg[ \frac{{($^{66}$Zn/ $^{64}$Zn)$_{sample}$}}{{( $^{66}$Zn/ $^{64}$Zn)$_{standard}$}} - 1 \Bigg] \times $1000\textperthousand$

\end{document}

• Your expression must be set in math mode, thus enclosed in $...$ delimiters or $$...$$. – Steven B. Segletes Jun 9 '15 at 19:20
• Doesn't answer your question - just a tip: it's usually preferable to make "sample" and "standard" upright, as in Heiko Oberdiek's answer – Au101 Jun 9 '15 at 19:36
• Continuing what @Au101 said, do this with \text{sample}, etc. Note the currently-bad kerning between the R and D of 'standard'. – Sean Allred Jun 9 '15 at 19:37
• While all the answers using mhchem are technically correct, the chemmacros package is newer, and has a number of features that mhchem does not. – Canageek Jun 10 '15 at 18:50

You should use the mhchem package, which eases typesetting chemical reactions/compounds. If the chemgreek package is installed, mhchem will load it so as to have upright greek letters:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[TS1,T1]{fontenc}
\usepackage{amsmath}
\usepackage{newtxtext,newtxmath,amsmath}
\usepackage{mhchem, textcomp}

\begin{document}

$\ce{\delta^{66} Zn} = \left[ \frac{\bigl(\ce{^{66}Zn}/\ce{^{64}Zn}\bigr)_\text{sample}}{\bigl(\ce{^{66}Zn}/ \ce{^{64}Zn}\bigr)_\text{standard}} - 1 \right] \times 1000\,\text{\textperthousand}$

\end{document}


• This works!!! Thank you so much. I can use the \Large command before the equation and everything is systematically enlarged. Thanks a bunch. – Harry Jun 9 '15 at 19:50
• What does the delta represent in the equation? (I have my doubts that it should be upright here…) – cgnieder Jun 11 '15 at 16:19
• @clemens: No idea. I'm not a chemist. The mhchem doc seems to say Greek letters in chemistry are upright. Anyway, italic Greek letters in maths is not universal: the French use (and possibly the Russian) is upright Greek letters and uppercase Latin letters. – Bernard Jun 11 '15 at 16:45
• I know about the upright letters in chemistry (I wrote chemgreek): mostly that's in chemical names. A variable still is a variable and should be italic... – cgnieder Jun 11 '15 at 16:52
• Not in France, unless it's a lowercase Latin letter. Further more it has the advantage of a less uniform look on the page, easing readability, in my opinion. – Bernard Jun 11 '15 at 16:56

For example, package mhchem can be used to typeset the chemical formulas. The letters of a chemical symbol are usually put upright. The permille sign can be set as \textperthousand in text mode (\text with package amsmath or amstext or \mbox). The example goes a step further and uses package siunitx for setting the number with "unit" permille.

\documentclass{article}
\usepackage{amsmath}
\usepackage[version=3]{mhchem}
\usepackage{textcomp}
\usepackage{siunitx}
\DeclareSIUnit\permille{\text{\textperthousand}}

\begin{document}
$\delta\, \ce{^{66}Zn} = \left[ \frac{\ce{(^{66}Zn/^{64}Zn)_{sample}}} {\ce{(^{66}Zn/^{64}Zn)_{standard}}} - 1 \right] \times \SI{1000}{\permille}$
\end{document}


How about this? I've used the mhchem package for the Zn. I highely recommend it to simplify any chemical typesetting needs.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[version=3]{mhchem}

\begin{document}

\begin{equation*}
\delta\thinspace\ce{^{66}Zn} = \Biggl[\frac{(\ce{^{66}Zn}/\ce{^{64}Zn})_{\text{sample}}}{(\ce{^{66}Zn}/\ce{^{64}Zn)}_{\text{standard}}} - 1\Biggr] \times 1000 \text{\textperthousand}
\end{equation*}

\end{document}


The edited version is almost identical to the other solution. \text{} can be used in math mode to type the \textperthousand. This symbol isn't available in all font encodings, hence the fontenc package.

• Thank you so much. This helps partially. Could I possibly replace the % by permille symbol? the \permil and \textperthousand commands do not seem to work with the proposed code. – Harry Jun 9 '15 at 19:29
• I added the \usepackage{newtxtext,newtxmath,amsmath} and that seems to fix it. However I cannot increase the size of the equation. I used the following code. \LARGE \delta\thinspace\ce{^{66}Zn} = \Biggl[\frac{(\ce{^{66}Zn}/\ce{^{64}Zn})_{sample}}{(\ce{^{66}Zn}/\ce{^{64}Zn)}_{standard}} - 1\Biggr] \times 1000 \textperthousand – Harry Jun 9 '15 at 19:31
• I am not sure how I can insert codes within comments. I am sorry if the earlier comment looks scrambled – Harry Jun 9 '15 at 19:32
• Use code. Note also the bad kerning between R and D in 'standard' in your answer -- use \text{standard} (and everywhere else that's properly text) to fix this. – Sean Allred Jun 9 '15 at 19:40
• Excellent this is very helpful. Thanks a lot guys. Lastly, any idea of how I can increase the size of the equation by 50 or 60 % ? – Harry Jun 9 '15 at 19:44