More about properties of Morse oscillator

Using Birge-Sponer extrapolation we have analyzed the approximation of the potential of a real diatomic molecule by the Morse model, which implies a constant value of anharmonicity ωx. The real values of ωx*(v) for each vibrational level are estimated from transition frequencies between neighboring levels. The dependence of ωx* on the vibrational quantum number v up to dissociation is calculated from the literature data for the ground electronic state of H₂, O₂, Be₂, Li₂, ArXe, Xe₂, Kr₂ and the excited state of Li₂. Characteristic features of deviations of the anharmonicity parameter x* - x from the Morse model are described.