Collect. Czech. Chem. Commun. 1989, 54, 3107-3116

Determinable parameters of the effective rotational Hamiltonians for excited vibrational states of semirigid symmetric top molecules of C4v, D4, D2h, andD2d symmetry

Kamil Sarkaa and Dušan Papoušekb

a Faculty of Pharmacy, Comenius University, 832 32 Bratislava
b The J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 182 23 Prague 8


A general method is described for obtaining the S functions which in the contact transformation of the vibration-rotation Hamiltonian of semirigid molecules with the fourfold symmetry axis eliminate the rotational and vibrational l-type operators and the Δk = ±4 centrifugal distortion operators from the λH1 terms of the expanded Hamiltonian. Explicit expressions are given for the vibration-rotation energy levels with independent effective spectroscopic parameters. Expressions are also given for the splittings of energy levels with essential resonances.