Angular distributions of electrons in the electronic excitation of O2

Expressions for the angular distributions of electrons in the excitation of O2 to the a 1 Delta g and to the b 1 Sigma g+ states are given. Assuming that both processes proceed via the O2- 2 Pi g state, theory agrees very well with experiment. Further, the mechanism for the parity unfavoured 3 Sigma g- to 1 Sigma g+ transition is demonstrated to be rotational-electronic coupling.