By employing the asymptotic iteration method (AIM), we solved the three-dimensional time-independent Schrödinger equation with the anharmonic Eckart potential model. The expression for the eigensolution of the anharmonic Eckart potential was obtained. With the help of the ro-vibrational energy spectra obtained, we derived the expressions for the ro-vibrational partition function and other thermodynamic functions, via the Euler MacLaurin formula. Effects of temperature and upper bound vibration quantum number on the thermodynamic functions of anharmonic Eckart potential were discussed for some diatomic molecular systems. It has been established that unique critical temperatures of ro-vibrational entropy and ro-vibrational specific heat capacity exist for the selected diatomic molecules.

By employing the Nikiforov–Uvarov functional analysis (NUFA) method, we solved the radial Schrödinger equation with the shifted Morse potential model. The analytical expressions of the energy eigenvalues, eigenfunctions and numerical results were determined for selected values of the potential parameters. Variations of different thermodynamic functions with temperature were discussed extensively. Different quantum information theoretic measures, including Shannon entropy, Fisher information and Fisher–Shannon product of the shifted Morse potential, were investigated numerically and graphically in position and momentum spaces for the ground and the first excited states. The quantum information theories considered satisfied their corresponding inequalities, including Bialynicki–Birula–Mycielski, Stam–Cramer–Rao inequalities and the Fisher–Shannon product relation.