Add checks: hydrogens present, types of atoms

[cisert]

https://github.com/josejimenezluna/delfta/blob/ca79d57c862e3b1c626e8abc9f5cf74f3a64b620/delfta/calculator.py#L54

• mol.addhs()
• check for atom types that are not included in QMugs

[cisert]

• print an INFO when adding hydrogens
• print a WARNING when unsupported atom types are present, and skip calculation for that molecule

[cisert]

• check for charges → QMugs only contains uncharged molecules, so let's stick to that

[josejimenezluna]

only missing the check for charges now

[josejimenezluna]

@cisert the atom object in pybel has both a formalcharge and a partialcharge attribute.

https://open-babel.readthedocs.io/en/latest/UseTheLibrary/Python_PybelAPI.html

Which should we be checking?

[cisert]

@josejimenezluna: formal charge :) (difference between #protons and #electrons)