A VIBRATIONAL HAMILTONIAN MODEL FOR TRIATOMIC-MOLECULES BASED ON THE KRATZER AND POSCHL TELLER POTENTIALS

A Hamiltonian model to describe molecular vibrations of triatomic molecules is proposed. The Hamiltonian is based on the use of the Kratzer potential variable for the stretching motions and a perturbed Poschl Teller potential for the bending one. The perturbation and variational treatments to compute the vibrational energies of this Hamiltonian can be developed using a zero-order system that includes part of the couplings between the stretching and bending motions. All the matrix elements involved in these calculations can be then evaluated in closed form. A numerical application to the HCN molecule is made. (C) 1994 John Wiley & Sons, Inc.