Ro-vibrational energies of caesium molecules with the Tietz-Hua oscillator

Ro-vibrational energies of caesium molecules in the excited electronic state 3³∑_g⁺ have been calculated by solving the Schrödinger equation for Tietz-Hua potential by applying a Pekeris-type approximation to the centrifugal term. The obtained results are compared with those obtained via improved Manning-Rosen potential and with the experimental Rydberg–Klein–Rees (RKR) data. It has been demonstrated that the Tietz-Hua potential is one of the best potential energy functions in fitting experimental RKR data for Cs₂ (3³∑_g⁺) molecule. The ro-vibrational energy levels, calculated by using Tietz-Hua potential, are in excellent agreement with the experimental data with an average deviation less than 0.001% in the most worst cases.