More accurate ro-vibrational energies for SiF +(X 1Σ+) molecule

Abstract

The most appropriate potential energy function for the X 1Σ+ state of SiF+ molecule has been specified by comparing the vibrational energies obtained via special cases of the general molecular potential (GMP) which are Morse, improved Rosen-Morse, modified Rosen-Morse, improved Manning-Rosen and Tietz potentials with the vibrational energies obtained in the presence of improved generalized Pöschl-Teller (IGPT) potential and experimental data. It has been shown that the improved Rosen-Morse potential is better than the other well-known potential energy functions in fitting experimental energies of SiF +(X 1Σ+) molecule. By using relativistic rotational-vibrational energy eigenvalue relation for Rosen-Morse potential in improved form which is acquired by solving the Dirac equation under the GMP and Pekeris type approximation, the more accurate ro-vibrational energies of SiF +(X 1Σ+) molecule have been obtained. It has been demonstrated for SiF +(X 1Σ+) molecule that in order to procure more proper ro-vibrating energies for the SiF +(X 1Σ+) molecule, a Pekeris-type approach to the centrifugal term is better than the improved Greene-Aldrich in getting more accurate ro-vibrational energies.