Selection Rules for Electric Dipole Radiation

1.  ΔL = 0 (usually not), ± 1, but Δl = ± 1 for the e^- involved.

2.  ΔS = 0, multiplicity does not change.

3.  ΔJ = 0, ± 1, except J = 0 → J = 0.

4.  Δl = ± 1, only one electron jumps, (for the Russell-Saunders coupling).  Hence parity must
     change.

5.  ΔM_J = 0, ± 1, except 0 → 0 iff ΔJ = 0.