Anharmonic potential function, geometry, and energy levels of SiH3
1991; Elsevier BV; Volume: 147; Issue: 2 Linguagem: Inglês
10.1016/0022-2852(91)90071-h
ISSN1096-083X
AutoresV. Špirko, W.P. Kraemer, Jaroslav V. Burda,
Tópico(s)Spectroscopy and Laser Applications
ResumoAn effective potential energy function of the silyl radical SiH3 was determined by fitting a general analytic expression to the experimental laser diode data of SiH3 [C. Yamada and E. Hirota, Phys. Rev. Lett. 56, 923–925 (1986)] and to the resonance enhanced multiphoton ionization (REMPI) spectra of SiH3 and SiD3 [R. D. Johnson, B. P. Tsai, and J. W. Hudgens, J. Chem. Phys. 9, 3340–3359 (1989)] and by making use of accurate ab initio results calculated in this study supplemented by additional literature data. In order to obtain a numerically stable and physically meaningful solution of the fitting procedure, the inversion potential constants were constrained by adopting the reduced double-minimum potential concept and by keeping several (in-plane) and (in-plane)-(out-of-plane) force constants fixed at their previously determined ab initio values. The actual fitting was performed using a modified version of the nonrigid inverter Hamiltonian approximation [V. S̆pirko, J. Mol. Spectrosc. 101, 30–47 (1983)] in which a variational description of the (x-y) Coriolis interaction between the ν2 and ν4 vibrational modes is introduced. The fitted potential energy function provides roinversional energy levels in excellent agreement with the available experimental data. Present predictions of the unobserved roinversional transitions of the ν4± and (ν2 + ν4)± vibrational levels are therefore expected to be reliable.
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