Calculation of parity-violation effects for the C-F stretching mode of chiral methyl fluorides

Relativistic four-component electronic structure calculations including the nuclear spin-independent parity-odd (P-odd) electroweak neutral current are presented for the study of the breaking of mirror symmetry in the vibrational structure of chiral molecules. The structures of all four chiral CFXYZ compounds (X,Y,Z=H,Cl,Br,I) were optimized by coupled cluster techniques with a subsequent normal-mode analysis. Vibrational wave functions for the C-F stretching mode along the normal coordinate were produced numerically from calculated coupled cluster potential-energy curves that yield the following left-right parity-violating differences in frequency for the C-F stretching fundamental transitions: 1.7 mHz for CHFClBr, 11.6 mHz for CFClBrI, 23.7 mHz for CHFClI, and 50.8 mHz for CHFBrI. In order to measure these differences in the spectra of the two enantiomers of these chiral molecules, a two orders of magnitude improvement in the resolution of current precision optical spectroscopy is required.