Ro-vibrational energy analysis of Manning–Rosen and Pöschl–Teller potentials with a new improved approximation in the centrifugal term

Two physically important potentials (Manning–Rosen and Pöschl-Teller) are considered for the ro-vibrational energy in diatomic molecules. An improved new approximation is invoked for the centrifugal term, which is then used for their solution within the Nikiforov–Uvarov framework. This employs a recently proposed scheme, which combines the two widely used Greene–Aldrich and Pekeris-type approximations. Thus, approximate analytical expressions are derived for eigenvalues and eigenfunctions. The energies are examined with respect to two approximation parameters, $$\lambda $$ and $$\nu $$ . The original approximations are recovered for certain special values of these two parameters. This offers a simple effective scheme for these and other relevant potentials in quantum mechanics.