Ab initio calculation of the electronic transition moments for excited states of the H2 molecule

Ab initio MRCI electronic dipole transition moments were calculated for the singlet and tripler molecular states contributing to free-free and free-bound absorption in the far wings of the Lyman alpha and Lyman beta lines of hydrogen atom perturbed by another hydrogen atom in its ground state. Results are presented for internuclear distances ranging from 1.0a(0) to 50a(0), and for transitions between the X(1)Sigma(g)(+) ground state to all (1)Pi(u) and (1)Sigma(u)(+) states and between the b(3)Sigma(u)(+) state to all (3)Pi(g) and (3)Sigma(g)(+) states that dissociate at large internuclear distances into H (n = 2, 3) + H (n = 1). These results compare well with the previous theoretical calculations available for a few transitions. (C) 1999 Academic Press.