WHAT DOES THE TERM “VIBRONIC COUPLING” MEAN?

Abstract

Abstract— The term usually referred to as vibronic coupling is discussed. Various adiabatic approximations are exactly defined in an effort to remove the existing ambiguities. The various approaches for improving approximate wavefunctions to obtain more exact wavefunctions are discussed. Transition dipole moments between two vibronic states are evaluated by the different methods, and the mutual relationship among the methods is discussed.