Simulation of the vibrational-rotational energy levels of D218O, HD18O, D217O, and HD17O molecules by the effective Hamiltonian approach

Abstract

The vibrational-rotational energy levels of the first and second triads and the first and second hexads of the D₂¹⁸O, HD¹⁸O, D₂¹⁷O, and HD¹⁷O molecules are simulated on the basis of the Watson-type Hamiltonian and the rotation operator written in terms of the Padé–Borel approximants. Rotational, centrifugal distortion, and resonance constants and mixing coefficients of the resulting wave functions are found by the least squares method. The resonance interactions are analyzed. The predictive capability of the effective Hamiltonian parameters found is examined for the long extrapolated rotational quantum numbers.