Symmetry vibronic wavefunction basis set and Hamiltonian representation for XY 3Z molecules near a doubly degenerate Jahn-Teller electronic state in the C 3v point group

Abstract

Methodology based on the crude adiabatic approximation is presented for the complete linear and quadratic vibronic coupling of a degenerate E electronic state to the 3e 1 and 3e vibrational modes in the case of XY 3Z molecules with C 3v symmetry. First we present a method for building a symmetry adapted vibronic wavefunction basis set which block diagonalizes the Hamiltonian representation. Secondly we report the representation of the electronic Hamiltonian in the crude adiabatic approximation for XY 3Z molecules with C 3v symmetry. Computer codes developed for solving the vibronic coupling are also briefly reviewed. Finally some results are given with reasonable force constants and different choices of coupling constants for the limited dynamic Jahn-Teller E⊗e coupling.