Coupled-cluster and multireference configuration interaction study of the low-lying excited states of the H2O2-H2O complex.

Ab initio molecular orbital methods have been employed to determine the molecular structure, vibrational frequencies, and stability of the H(2)O(2)-H(2)O complex. These parameters were determined using coupled-cluster methods with Dunning correlation consistent basis sets. Vertical excitation energies for the lowest four excited states are calculated with the multireference internally contracted configuration interaction methods and coupled cluster equation of motion methods. No significant difference was observed between the first vertical excited state energies of H(2)O(2) within the H(2)O(2)-H(2)O complex.