Commutator perturbation method in the study of vibrational-rotational spectra of diatomic molecules

The commutator perturbation method, an algebraic version of the Van Vleck-P rimas perturbation method, expressed in terms of ladder operators, has been applied to solving the eigenvalue problem of the Hamiltonian describing th e vibrational-rotational motion of a diatomic molecule. The physical model used in this work is based on Dunham's approach. The method facilitates obt aining both energies and eigenvectors in an algebraic way. (C) 2000 John Wi ley & Sons, Inc.