units are almost entirely undocumented, everywhere

[ExpHP]

I seldom bother documenting units because I've always wanted to use newtypes for units. However, those are such a hassle to adopt, and I should probably just face the facts that it's never going to happen.

It feels ironic that rsp2 already even has newtypes for some things like Mass, and that even these do not specify what the units are.

[ExpHP]

For the record, except where noted:

• All masses are atomic units
• All frequencies are wavenumber (cm^-1)
• All cartesian coordinates are Angstrom
• All energies are eV
• All reciprocal cartesian coordinates are Angstrom^-1
  • rsp2 defines the reciprocal lattice as inv(L^T), without a 2pi factor (to any power). This similarly affects k vectors. Rather, the 2pi factors appear in phase factors (usually written in the form exp(i * 2 * pi * dot(k, x))).
• Angles are almost always in radians, however, degrees are usually used for display purposes and input