Problem 0. What are the quantum numbers (,,) corresponding to atomic orbitals 1s, 2s, 2p, 3s, 3p, 3d etc.? When there is degeneracy, e.g. ,,, or 2,22,,,, how to use linear combination of to generate them? Note that, are complex for 0. Instead of linear combinations, can you use the real part and imaginary part of a complex to indicate some orbital wave functions?