Improve type annotations and comments for io.cif

[DanielYang59]

Summary

• Add type annotations and tweak comments for io.cif
• Minor code format tweak
• Simplify "check to see if" to "check if" in comments
• Remove if __name__ == "__main__" from core.libxcfunc (legacy from another PR)

Potentially Breaking Changes (very unlikely)

1. Make parse_oxi_states and parse_magmoms of CifParser private methods. Rationale:

   • These two parse methods are used exclusively for the private _get_structure method to parse corresponding properties from the file.

2. Remove unnecessary lattice argument from parse_magmoms method (now private). Rationale:

   • This argument is only used to check if Lattice is None, and could be done outside this method.
     

     pymatgen/pymatgen/io/cif.py

     Lines 850 to 869 in 2e1c301

     	@staticmethod
     	def parse_magmoms(data, lattice=None):
     	"""Parse atomic magnetic moments from data dictionary."""
     	if lattice is None:
     	raise ValueError("Magmoms given in terms of crystal axes in magCIF spec.")
     	try:
     	magmoms = {
     	data["_atom_site_moment_label"][i]: np.array(
     	[
     	str2float(data["_atom_site_moment_crystalaxis_x"][i]),
     	str2float(data["_atom_site_moment_crystalaxis_y"][i]),
     	str2float(data["_atom_site_moment_crystalaxis_z"][i]),
     	]
     	)
     	for i in range(len(data["_atom_site_moment_label"]))
     	}
     	except (ValueError, KeyError):
     	return None
     	return magmoms

[DanielYang59]

@janosh. Could you please review this as well? Thanks!

[janosh]

thanks @DanielYang59, this looks good! 👍

[DanielYang59]

Thanks for reviewing!