A new theoretical model of an effective Hamiltonian for nonrigid H2X-type molecules, based on the generating function approach, is applied to the experimental energy levels (R.A. Toth, Appl. Opt. 33 (1994) 4851-4867) of the first hexad of interacting states of H2O. The results of simultaneous fitting rotational levels of the six vibrational states of H2O up to J= 8, up to J = 10, and up to J = 15 are discussed. The experimental energy levels for J ≤ 8, for J ≤ 10, and for J ≤ 15 are fitted with an average discrepancy σ = 3.9 x 10-3 cm-1, σ = 6.1 x 10-3 cm-1 and σ = 10.5 x 10-3 cm-1, respectively. In the final fitting of 749 energy levels the additional new experimental energies were used and in this case σ = 13.6 x 10-3 cm-1. The influence of interaction between the first and second hexads of H2O molecule is also discussed.
ASJC Scopus subject areas
- Structural Biology
- Organic Chemistry
- Physical and Theoretical Chemistry
- Atomic and Molecular Physics, and Optics