# Write cursive l letter in chemical formula with chemmacros package

How can I replace the letter l in HCl with ℓ so it becomes HCℓ when using chemmacros? I would like to avoid confusion between l, 1 and I which look very similar.

One option:

\documentclass{article}
\usepackage{chemmacros}
\begin{document}

\ch{HC$\ell$}
\ch{HC$\ell$ + NaOH -> NaC$\ell$ + H2O}\par

\end{document}


UPDATE: Maybe the \ell from stix font package is more like you want it:

\documentclass{article}
\usepackage{stix}
\usepackage{chemmacros}

\begin{document}
\ch{HC$\ell$}\par
\ch{HC$\ell$ + NaOH -> NaC$\ell$ + H2O}\par

\end{document}


• Your answer is a good apporach but there is a slight difference : $\ell$ gives an italic ℓ in the final document while I would the upright one. Jan 19, 2021 at 23:30
• Related: Typeset an upright ell
– Werner
Jan 19, 2021 at 23:45
• @ Fizika Scienco see update Jan 20, 2021 at 0:15

First things first: chemmacros does not provide chemical formulas. With standard settings it loads the package chemformula so lets assume you meant that package.

You can tell chemformula to use ℓ instead of l. Of course you need a font that has the letter. Compiled with LuaLaTeX this example gives:

\documentclass{article}
\usepackage{libertine}

\usepackage{chemformula}
\NewChemCompoundProperty{l}{ℓ}

\begin{document}

\ch{HCl + 1 I2}

\end{document}


Or like @Roland's suggestion:

\documentclass{article}

\usepackage{chemformula}
\NewChemCompoundProperty{l}{$\ell$}

\begin{document}

\ch{HCl + 1 I2}

\end{document}


BTW depending on the font the real issue might already be solved by itself:

\documentclass{article}
\usepackage{libertine}
\begin{document}
1lI
\end{document}