Extra selection rules

Publisher Website
Google Scholar
Abstract
The recognition of antiunitary symmetry in a quantum mechanical system is considered in relation to selection rules. It is shown that the interaction of unitary symmetry and the anti‐invariance of matrix elements under antiunitary operators can produce extra selection rules in magnetic systems. The criteria obtained for the occurrence of these additional selection rules are presented in the form of group character tests, and in a special case provide an application for the symmetrized and antisymmetrized squares of group representations.