Vibrational Spectra Obtained from High Quality Potential Energy Surfaces Spanned by Low Level Normal Coordinates - Application to CHFClI and CDFClI

Guntram Rauhut (1) , Peter Schwerdtfeger (2) , Sandra Heislbetz (3)

1 Institute of Theoretical Chemistry
2 Centre of Theoretical Chemistry and Physics
3 Institute of Theoretical Chemistry

The impact of approximate normal coordinates for spanning high level potential energy surfaces on vibrational frequencies is studied within the framework of vibrational SCF and configuration interaction calculations (VCI). The use of low level normal coordinates avoids expensive geometry optimizations and harmonic frequency calculations and thus allows for a significant reduction in CPU time. Benchmark calculations are provided for a set of molecules ranging from 5 to 7 atoms. An application to CHFClI and CDFClI shows that this approximation still allows for very accurate results. These molecules are of particular interest for studying parity violation effects.

Mots clés: Physical Sciences

Guntram Rauhut, Peter Schwerdtfeger, Sandra Heislbetz. Vibrational Spectra Obtained from High Quality Potential Energy Surfaces Spanned by Low Level Normal Coordinates - Application to CHFClI and CDFClI. Molecular Physics, 2007, 105 (10), pp.1385-1394. ⟨10.1080/00268970701348741⟩. ⟨hal-00513095⟩