A PRINCIPAL COMPONENT ANALYSIS OF THE METHYL-FLUORIDE POLAR TENSORS

The principal component method is applied to the analysis of the alternative polar tensor data set values for CH3F and CD3F. Moller-Plesset perturbation and configuration interaction ab initio wavefunction results are necessary for a secure selection of the correct polar tensor values from the sets of values satisfying the isotopic invariance criterion for the A1 symmetry derivatives. The preferred polar tensor values corresponding to the E symmetry species can only be determined using Coriolis interaction information, the isotopic invariance criterion and molecular orbital results at the Moller-Plesset perturbation or configuration interaction levels. The results reported in this paper are in agreement with those obtained previously using the isotopic invariance criterion, Coriolis interaction information and the results of CNDO/2 molecular orbital calculations.