A new ab initio calculational method for simulations of the Raman opti
cal activity spectra is proposed. The method is based on the sum-over-
states formalism (SOS). Unlike the finite difference coupled-perturbed
calculations (CP) used previously, the new scheme provides analytical
derivatives of the polarization tensors and is less demanding with re
spect to the computer power. Although the new method is not suitable f
or accurate benchmark calculations, similar accuracy of the SOS and CP
results was observed for the spectra of alpha-pinene and trans-pinane
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