The ab initio calculation of the band origin and vibrational frequencies of the Ã-X̃ system of HNCl using the non-rigid bender hamiltonian

Abstract

A three-dimensional fit of ab initio MRD CI potential data has been made for the lowest two electronic states of the HNC1 molecule (X̃ 2A″ and à 2A'), and the corresponding vibrational frequencies and rotational energies have been computed using the non-rigid bender Hamiltonian. For the ground state the vibrational frequencies obtained are ν 1 = 2942 cm −1, ν 2 = 1232 cm −1, and ν 3 = 549 cm −1, while the corresponding values for the first excited state are 3524,947 and 836 cm −1 respectively. We calculate T c(à 2A') 16200 cm −1, T o(à 2A') = 16400 cm −1, and the Franck-Condon maximum, Ã(0,3,1)-X̃(0,0.0), is calculate at 19200 cm −1(5200 Å).