Generalized selection rules: An augmentation procedure for the determination of symmetry invariants

A group Augmentation procedure is presented for the analytic determination of tensional invariants of arbitrary order for all point groups. The results are an ideal pratical adjunct to the generalized selection rule approach, which focuses predominantly on the concept of symmetry invariant operator products, and reduces in the non-quantum limit to the definition of classical tensorial invariants. The relationship to rotational averages is discussed, and some applications to spectroscopic processes are considered.