Accession Number : ADA304232

Title :   Ab Initio Calculation of Vibrational Circular Dichroism Spectra Using Accurate Post-Self-Consistent-Field Force Fields: trans-2,3-Dideuteriooxirane.

Descriptive Note : Final rept. Jan 92-Jan 93,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Stephens, P. J. ; Devlin, F. J. ; Jalkanen, K. J. ; Chabalowski, C. F.

PDF Url : ADA304232

Report Date : FEB 1996

Pagination or Media Count : 29

Abstract : The ab initio calculation of harmonic force fields using post-self-consistent (post-SCF) methods has recently increased greatly in efficiency. As a result, accurate post-SCF harmonic force fields are now achievable for experimentally accessible chiral molecules. This in turn, permits for the first time, comparison to experiment of ab initio predictions of vibrational circular dichroism (VCD) spectra based on accurate harmonic force fields. This advance is exploited here in the calculation of the VCD spectrum of trans-2,3-dideuteriooxirane using a large basis set MP2 force field. Excellent accord with recent experimental work is achieved. With the exception of C-H and C-D stretching modes, residual differences between predicted and experimental VCD intensities can be attributed to the incomplete inclusion of correlation in the calculation of atomic axial tensors. jg p3

Descriptors :   *COMPUTATIONS, *CIRCULAR, *DICHROISM, *VIBRATIONAL SPECTRA, OPTICS, QUANTUM CHEMISTRY, MOLECULES, COMPARISON, HARMONICS, CARBON, HYDROGEN, HYDROCARBONS, TENSORS, ATOMIC PROPERTIES, AXIAL FLOW.

Subject Categories : Organic Chemistry
      Physical Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Optics
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE