Molecular Rydberg states. VII. Water

Abstract

The optical absorption spectra of H2O and D2O are reported at various pressures for 2000?λ?950 Å. The 1670 Å band is vibrationally structured (ν2 bend) and the excited 1B1 state contains a considerable intravalence 4a1 component. The 1280 Å state 3sa1; 1A1 is linear and dominantly Rydberg. A Renner–Teller analysis of the 1280 Å band leads to detection of a perturbing state at 1365 Å which may be assigned as a bent, heavily Rydberg 3sa1; 1B1 state. A reanalysis of K-shell excitation spectra bolsters this 3sa1; 1B1 assignment. Isotope shift studies in the 1130–980 Å region lead to some vibronic reassignments. The terminal state of the 968 Å absorption band is a linear 5sa1; 1A1 state. In sum, a total of 21 electronic states, comprising fragments of six Rydberg series, have been assigned.