Spectroscopic constants of alkali halides and hydrides using modified T-Rittner model

Abstract

The T-Rittner model derived from quantum mechanical exchange perturbation theory is modified by incorporating (i) new values of molecular state polarizabilities, (ii) the recent values of van der Waals potentials estimated from the Kirkwood–Muller (KM) formula, and (iii) the repulsive hardness parameters evaluated from the overlap integrals using the exchange charge model (ECM). With the help of this modified potential model we calculate values of binding energy W, dipole moment μ, vibrational frequency ωe, vibrational anharmonicity constant ωeXe, and rotational constant αe for diatomic molecules of alkali halides and hydrides. The results obtained in the present study are compared with the experimental data. A good agreement between calculated and experimental values supports the validity of the modified T-Rittner model used in the present study.