ELECTRONIC POLARIZABILITIES, POTENTIAL FUNCTIONS, AND SPECTROSCOPIC CONSTANTS FOR DIATOMIC-MOLECULES OF ALKALI-HALIDES AND ALKALI HYDRIDES

The two different approaches for the evaluation of molecular state electronic polarizabilities of ions based on Seitz-Ruffa (SR) energy level analysis and Wilson-Curtis-Coker model are critically analyzed by calculating the values of dipole moments within the framework of the original Rittner and the modified T-Rittner models. It is found that the polarizabilities based on SR energy level analysis along with the T-Rittner model are distinctly superior. These polarizabilities are used for determining spectroscopic constants for diatomic molecules of alkali halides and alkali hydrides. Various potential functions for the overlap repulsive energy proposed so far are used to estimate the binding energy and its various order derivatives. A comparison of calculated values with the experimental data shows that the modified Varshni-Shukla potential, among seven traditional potentials, and the Narayan-Ramaseshan (NR) potential, among three ion-dependent potentials, yield the best agreement with experimental data. Using these potentials we have calculated the values of spectroscopic constants viz. vibrational anharmonicity constant, rotational-vibrational coupling constant, and higher order spectroscopic constants. It is concluded that the results obtained by NR potential are distinctly superior to those obtained by the modified Varshni-Shukla potential function.