A vibrational configuration interaction program for energies and resonance widths

Abstract

We present a computer program to calculate energies and Feshbach golden-rule resonance widths of systems described by a two-dimensional vibrational Hamiltonian. The steps involved are evaluation of matrix elements over the potential and basis functions, diagonalization of a vibrational configuration interaction matrix, projection of the resonance component out of a new basis set (involving vibronic-interaction-like integrals), and evaluation of the transition matrix elements.