Photodissociation processes in the HCl molecule

Abstract

Various ab initio methods have been employed for the study of photodissociation processes in the HCl molecule. Potential curves for selected singlet and triplet states and dipole transition moments between singlet states have been calculated. The transition moments vary significantly with internuclear distance for all states studied. The lifetime of the B 1Σ+ state is predicted to be 3 ns. The calculations show that photodissociation of HCl occurs by absorption into the repulsive A 1Π state and by absorption into the bound C 1Π state, followed by predissociation. The theoretical photodissociation cross sections for the A 1Π state and oscillator strengths for the C 1Π state are in good agreement with experimental data. The contributions from other excited states are investigated. The photodissociation rate of HCl in diffuse interstellar clouds is computed.