An ab initio study for the photodissociation of HCl and HF

Abstract

ABSTRACT Detailed studies of HCl and HF photodissociation are required for an in-depth understanding the chlorine and fluorine chemistry in Venus and exoplanets. Here, we present an ab initio study of photodissociation of HCl and HF. Except for the widely studied A 1Π←X 1Σ+ photodissociation process, the ground-state photodissociation processes for HCl and HF via higher excited states are considered. State-resolved cross-sections are computed for nine photodissociation processes of HCl from a total of 871 ground rovibrational levels. For HF, seven photodissociation processes are considered for the computation of state-resolved cross-sections from all the rovibrational levels in the ground state. Subsequently, temperature-dependent cross-sections for the considered transition processes of HCl and HF are estimated from 0 to 10 000 K with a grid of 34 temperatures. Careful comparisons with the recent ExoMol study and the Leiden Observatory database are made. The photodissociation rates in the interstellar and blackbody radiation fields are also discussed.