The lowest energy electronic transitions in the weakly bound van der Waals complex of water and oxygen (H 2 O•O 2 ) are studied using ab initio methods. The vertical excitation energies for the two low-lying singlet states are calculated...
moreThe lowest energy electronic transitions in the weakly bound van der Waals complex of water and oxygen (H 2 O•O 2 ) are studied using ab initio methods. The vertical excitation energies for the two low-lying singlet states are calculated with the complete active space self-consistent field and multireference configuration interaction ͑MRCI͒ methods, and are compared to those calculated in the oxygen molecule. The MRCI calculations predict blueshifts of about 150 and 250 cm Ϫ1 for the transition frequencies on formation of the complex. These calculated shifts can provide assistance towards the spectroscopic identification of H 2 O•O 2 .
