Vibration-rotation energies of tetrahedral XY4 molecules : Part II. The fundamental [nu]3 of CH4

Abstract

The matrix elements derived in the first paper of this series are used to compute the frequencies of the tetrahedral fine structure components of the rotational lines of the fundamental [nu]3 of CH4. The theoretically predicted frequencies are compared with the recent high resolution spectra of Plyler et al. A best fit for the splitting patterns is obtained with the following splitting constants: t224 = -2.93 x 10-3 cm-1, t134 = -4.5 x 10-6 cm-1, t244 = -5.0 x 10-6 cm-1. Analysis of the unperturbed frequency positions and the weak forbidden P and R branch lines gives the following rotational constants: B0 = 5.240 cm-1, D8 = 1.0 x 10-4 cm-1, B3(R = J) = 5.191 cm-1, B3(R = J + 1, J - 1) = 5.201 cm-1, [zeta]3 = 0.0547.