Inst High Energy Phys, Beijing 100039, Peoples R China
; Univ Three Gorges, Dept Phys, Yichang 443000, Peoples R China
; Tianjin Normal Univ, Dept Phys, Tianjin 300074, Peoples R China
; China Ctr Adv Sci & Technol, World Lab, Beijing 100080, Peoples R China
The stretching and bending vibrational spectrum and the intensities of infrared transitions in a tetrahedral molecule are studied in two boson-realization models, where the interactions between stretching and bending vibrations are described by a quadratic cross term and by Fermi resonance terms, called harmonically coupled and Fermi resonance boson-realization model, respectively. The later is a development of our recent model. As an example, the two models are applied to the overtone spectrum and the intensities of silicon tetrafluorde. Those models provide fits to the published experimental vibrational eigenvalues with standard deviations 1.956 cm(-1) and 0.908 cm(-1), respectively. The intensities of infrared transitions of its complete vibrations are calculated in the two models, and results show a good agreement with the observed data. (C) 1998 Academic Press.