AB-INITIO CALCULATION OF VIBRATIONAL CIRCULAR-DICHROISM SPECTRA USINGLARGE BASIS-SET MP2 FORCE-FIELDS

Ab initio calculations of the vibrational circular dichroism (VCD) spe ctra of 2,3-trans-d2-oxirane (1), 1,2-trans-d2-cyclopropane pane (2), 1-C-13-1,2,3-anti-d3-cyclopropane (3), and propylene oxide (4) based o n [ 5s4p2d/3s2p] MP2 harmonic force fields are reported. The results a re in perfect qualitative and good quantitative agreement with existin g experimental VCD spectra except in the C-H stretching region of 4 wh ere Fermi resonance occurs. Calculations for 1-3 using a larger [8s6p3 d/6s3p] basis set exhibit insensitivity to a substantial increase in b asis set size.