Ab initio calculation of molecular hydrogen electronic states’ properties: transition matrix elements among triplet electronic states

Abstract

The aim of this work is the ab initio study of the properties of the electronically excited states of the H2 molecule for progressively higher states. Computations are performed using the optimized full CI code which allowed us to make very accurate calculations of the energies of the molecular electronic excited states and of their properties, such as transition moments, fine structure constants (spin–orbit and spin–spin), non-adiabatic coupling matrix elements. Seventeen new transition matrix elements among the triplet electronic states dissociating to the second (H(1s)+H(2ℓ)) and third (H(1s)+H(3ℓ)) asymptotes have been calculated for internuclear distances ranging from 0.6 to 12 bohr. They involve the following upper electronic states: 4,5,6 , 4,5 , j3Δ g and 13Δ u. The potential energies of the 13Δ u and 43Π u electronic states have also been obtained for similar internuclear distances.