Collect. Czech. Chem. Commun. 1998, 63, 1321-1328

Water Photolysis in Rare Gas Environment: The CASPT2 Excited State H2O(A)-Ar Potential

Dana Nachtigallová, Petr Slavíček, Petr Nachtigall and Pavel Jungwirth

J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, 182 23 Prague 8, Czech Republic


The potential energy surface of the first excited state of the water-argon complex is explored at a multireference perturbation theory level as an initial step of the project aimed at the study and control of photodissociation in H2O-Arn (n = 1, 2, ..., 12) clusters. Ab initio calculations, which will serve as a basis for the construction of an analytical force field for dynamical simulations, reveal the anisotropy of the excited state surface and weak potential coupling between intermolecular and intramolecular degrees of freedom. The importance of the "cage effect" is demonstrated.

Keywords: CASPT2; H2O photodissociation; H2O-Argon complex; Ab initio calculations.