The vibrational spectrum of camphor from ab initio and density functional theory and parity violation in the C–C*–CO bending mode

The C–C*–CO bending mode in camphor (C* denotes a chiral carbon) as originally investigated for parity violation effects by Arimondo et al. [Opt. Commun. 23 (1977) 369] lies in the CO2 laser frequency range with the most intense transition at 1045 cm−1. The vibrational spectrum of camphor is, therefore, reinvestigated by ab initio and density functional calculations and compared with experimental results. This provides the basis for a local mode analysis which reveals that the C–C*–CO bending mode has only minute parity violation contributions (<10−5 Hz) to vibrational transitions far below the current detection limit of high resolution spectroscopy.