Mean-Square Amplitudes and Force Constants of Tetrahedral Molecules. II. Silicon Tetrachloride

The atomic distances and the mean-square amplitudes of silicon tetrachloride have been determined by the sector-microphotometer method. The possible sources of experimental errors have been thoroughly examined. The quadratic force constants of the potential function have been determined by the use of the mean-square amplitudes thus obtained, by combining them with the vibrational frequencies obtained from the Raman spectrum in the gaseous state. It has been shown that the errors of the force constants originate from those of the mean-square amplitudes by the same order of magnitude as from those of the frequencies.