Influence of non-adiabatic corrections on inverse calculation of the adiabatic function of the potential energy of diatomic molecules

Some fittings are made to treat the spectroscopic parameters so as to adjust not only the potential energy function but also the non-adiabatic parameters of diatomic molecules. Definitions of the effective reduced mass and the effective internuclear distance in relation to the rotational constant are used for this purpose. The detailed calculations for CO molecule are given.