An ab initio anharmonic force field of SiHCI₃

An ab initio quartic force field of SiHCl₃ is derived using the second-order Møller-Plesset perturbation theory and Dunning's correlation consistent triple-zeta basis set. After a minor empirical adjustment for the six diagonal quadratic force constants, most fundamentals of SiHCl₃ and SiDCl₃ agree with the experimental values within 1 cm⁻¹. Additionally the observed overtones, combinations and hot band centres can also be well reproduced. Vibrational analysis based on the second-order perturbation theory is carried out with the calculated force constants. Two sets of spectroscopic constants are predicted for ²⁸SiH³⁵Cl₃ and ²⁸SiD³⁵Cl₃, respectively.