LOWEST ORDER RELATIVISTIC CORRECTIONS TO THE ENERGIES OF THE B-1-SIGMA(U) STATE OF H-2

The lowest order relativistic corrections to the electronic energies have been computed for the B (1) Sigma(u) state of H-2 in the interval 1.0 less than or equal to R less than or equal to 30 a(0). The total correction at the equilibrium separation, R = 2.43 a(0) amounts to -2.126 cm(-1). The absolute shifts of the vibrational levels of H-2 change monotonically with v for v less than or equal to 27 from -2.090 to -1.538 cm(-1) as compared with the -1.918 cm(-1) shift of the dissociation limit. The computed shifts are used to place the v = 0 levels of H-2 and D-2 on a absolute energy scale and a comparison with experiment is performed.