Correlation, relativistic and adiabatic corrections to the ground state potential curve of the hydrogen molecule

Correlation, relativistic and adiabatic corrections are computed for the electronic ground state of the hydrogen molecule for r less than or equal to 12 a.u. In contrast to previous calculations (based on the numerical solution of the Schrodinger equation, mainly done by Wolniewicz et al.), our results are based on the ordinary ab initio treatment using a lour-component wave function with fully relativistically reoptimized basis sets and adiabatic corrections by the treatment developed in our laboratory. The calculated energies are fitted to the polynomial/exponential analytical function and the evaluated spectroscopic parameters are compared with those obtained in the same manner from the Wolniewicz data. The results presented show a good agreement with exact numerical calculations published previously.