Rotation vibration spectrum of potassium molecules via the improved generalized Pöschl‐Teller oscillator

Abstract In this work, we used the improved generalized Pöschl‐Teller potential (IGPT) to calculate the rotational‐vibrational (ro‐vibrational, hereinafter) energies of potassium molecules in the excited electronic state . In doing this, we first solved the Schrödinger equation for the (IGPT) by applying both the Pekeris‐type and the Greene‐Aldrich approximations to the centrifugal term. The obtained energy spectra are compared with that of the experimental Rydberg‐Klein‐Rees (RKR) data. We also showed that the IGPT potential is a good potential function in fitting experimental RKR data for the 39 K 2 ( ) molecule. Finally, we have proved that Pekeris‐type approximation is better than Greene‐Aldrich approximation in calculating the accurate ro‐vibrational energies spectra for the potassium molecular dimers.