Rydberg states in H2O

Abstract
Ionization and excitation energies for the Rydberg states (3,1B1, 3,1A2, 3,1A1 lying above the ground state 1A1) of the water molecule have been calculated via the multiple‐scattering X a (MSX a) method. Both singlet and triplet states have been computed self‐consistently. The first ionization energy of the molecule was also computed. In general, the results are in good agreement with experiment, and a few levels were found that have not been observed. The results were also compared with Hunt and Goddard's recent improved virtual orbital (IVO) calculation on H2O.
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