Over the years, I have written many latex macros for common tasks. Here are some that I use most frequently. These files may be incorporated into a document using \input{units}\input{nuclides}.

units.tex

This file contains common definitions of units and spacing commands. It is not as sophisticated as packages available from CTAN, but the macros are consistent with submission policies for the AAS journals. For example, to produde "10³⁴ ergs s^-1", write $10^{34}\nsp\ergs\nsp\second^{-1}$.

nuclides.tex

This file contains macros to produce nuclei names, set in roman font. Each nuclide name takes as an optional argument the atomic number A. If this argument is omitted, the A of the most abundant stable isotope for that element is used instead. For example, \carbon produces ¹²C, but \carbon[13] produces ¹³C.