Nonadiabatic perturbations in the spectra of molecular hydrogen

Abstract

The C1Пu state of H2 has a small hump in its potential due to the combination of an intermediate molecular attractive force and a long range repulsive van der Waal's force. This hump is large enough to allow the formation of pseudo-bound states above the dissociation limit of the C state. These bound states should show up as resonances in the photodissociation spectrum of molecular hydrogen, but they have not been observed. The B1[summation]u+ state is coupled to the C state via the A interaction which may affect the quasi-bound resonances. The photdissociation cross sections for the Lyman and Werner bands are calculated. T h e effect of the nonadiabatic interaction is accounted for by calculating the cross sections of the coupled B1[summation]u-C1Пu state. The coupled differential equations of the interacting B and C states were solved using an adapted version of NIEM suitable for two open channels. The cross sections are then weighed to a thermal distribution at 300K.