I would appreciate some guidance on how to format units that incorporate SI, molecules, and text.

Right now I am formatting the letters in chemicals or names as 'text' and the SI units, sub/super scripts and numbers in math.

For example, I would appreciate feedback on how to format the following for publication:

- meter squared leaf area per meter squared of ground: $m^2$leaf$m^{-2}$leaf
- grams carbon: $g$C
- carbon dioxide CO$_2$

This previous question about [what package should be used to typeset units] is similar, except that I am not convinced that I need to add another package like siunitx (publishers request that I minimize use of extra packages).

Thanks!

## Best Answer

Use the SIunits package. Note that SI units are to be typeset in roman type, not italics! And please don't mix information and units. “g C” (with a thin space) can mean only one thing, namely the product of the units gram and Coulomb. Mixing in information like C for carbon with the units is a cardinal sin. A major point of standardised units with a standardised notation is disambiguation – if you see an SI unit in a paper far from your own speciality you should still be able to understand what it means.

Please refer to the style guides at the NIST SI units home page for further details.