Electronic states of the XenHCl systems in gas and condensed phases

Systems formed by one Cl, one H, and one or several Xe atoms are considered by the semiempirical diatomics-in-ionic-systems (DIIS) method, which takes into account the charge delocalization in ionic states and the coupling between the neutral and ionic states. Calculations are performed both for gas-phase systems, such as van der Waals complexes and clusters XenHCl (n=1,2,4,8,12) and ionic molecules (HXen)+Cl−, and for systems formed in Xe solids doped by HCl molecules. The calculations give the structure of the systems, dissociation energies, and energies of electronic transitions. The calculations show, in particular, the existence of the ground-state ionic molecule (HXe)+Cl−, the decrease of the HCl electronic excitation energy in clusters and solids, and the increase of the emission photon energy of the ionic HXe+nCl− systems as compared to the Xe+nCl− molecule.