Ab initio study of HOCl, HCl, H2O, and Cl2 interacting with four water molecules

An ab initio calculations were derived of the adsorption of stratospherically relevant compounds HOCl, HCl, H2O and Cl2 on a water tetramer mimicking an adsorption site on the 0001 (basal) surface of hexagonal ice. The study focused on the geometric/electronic changes in both the adsorbates/adsorption site during their interactions. HOCl and HCl adsorbed with hydrogens oriented toward a water oxygen with the greatest interaction energies. Thus, the large binding energies of HOCl/HCl are not due to geometrical changes in the adsorbate or in the structure of the adsorption site.