Franck-Condon Factors for the Ionization of H2O and D2O.

Abstract

Franck-Condon factors have been calculated for vertical transitions of H2O and D2O involving both bond length and angle changes. It is shown that even in the harmonic oscillator approximation different Franek-Condon factors are obtained for positive and negative angle changes. The results are used to obtain the geometry of the ion ground state. Satisfactory agreement is obtained for the isotope effect on the vibrational transition probabilities. The effects of anharmonicity are discussed semi-quantitatively.