Jahn–Teller, pseudo Jahn–Teller coupling, and circular dichroism spectra of (E+A) e systemsa),b)

The vibronic coupling problem in a (E+A)e system of molecular levels is analyzed. Both Jahn–Teller and pseudo Jahn–Teller interactions are taken into account. The Jahn–Teller interaction is assumed to be linear and/or quadratic, whereas the pseudo Jahn–Teller interaction is taken linear in the doubly degenerate nuclear coordinate. Systems of vibronic levels are discussed for different sets of vibronic coupling parameters and energy gaps, and corresponding chiro−optical spectra are presented.