I have found out that there are two kinds of books on spectroscopy:
- chemistry prospective
- experimental physics prospective
I am looking for a book which contains more or less rigorous theoretical considerations, like fundamental symmetries and conservation laws, accompanied with QM derivations. Some of these topics are covered in regular QM courses, but not all of them and not in one place.
Most of the books leave mathematical arguments either incomplete, or drop them at all. I know that selection rules, for example, can be derived from transition amplitudes. They don't have to be hasty and handwaving.