Expressing capital M for molar in siunitx package

Question

The following code isn't valid but conveys my intention:

\SI{}{\micro\molar}

as in micro followed by a big M. I don't want to use the explicit form of micro moles per L raised to the negative one in this case.

Just FYI, NIST considers the M "obsolete": "The term molarity and the symbol M should no longer be used because they, too, are obsolete. One should use instead amount-of-substance concentration of B and such units as mol/dm3, kmol/m3, or mol/L." I use mol/L myself. https://www.nist.gov/pml/special-publication-811/nist-guide-si-chapter-8#862 — Michael Hoffman, Mar 16 '22 at 15:21
@MichaelHoffman I can not find if IUPAC, which should be the appropriate institution to do so, has deprecated the term. True that they say that it appears in older books. — Raoul Kessels, May 25 '22 at 07:22

score 28 · Accepted Answer · answered Sep 05 '11 at 23:46

Joseph Wright just answered a similar question on comp.text.tex:

Take a look at the section 'loading additional units' in the manual. In version 1, I did include \molar and \Molar, but tightened up on sticking to SI units (almost) exclusively for version 2. The suggested definitions are
\DeclareSIUnit\molar{\mole\per\cubic\deci\metre}
\DeclareSIUnit\Molar{\textsc{m}}

score 12 · Answer 2 · edited Nov 27 '12 at 16:14

12

According to the siunitx manual (page 14), you can create your own units easily by putting the following command in the preamble:

\DeclareSIUnit{\molar}{M}

edited Nov 27 '12 at 16:14

mrub

400

answered Sep 05 '11 at 23:37

You

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The Molar M should always be small caps! So \DeclareSIUnit{\Molar}{\textsc{m}} is better. It actually is part of siunitx anyways. – basseur Oct 12 '17 at 14:13

Expressing capital M for molar in siunitx package

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