Abstract
A model potential consisting of the exp-6 type dispersion and exchange repulsion terms, the Lippincott type hydrogen bond stretching terms and the electrostatic interaction terms between fixed atomic charges was applied for elucidation of the vibrational spectra of aspirin crystal. The frequencies of the optically active inter- and intramolecular normal modes were calculated. The proposed potential reproduced the factor group splittings between the infrared (IR) and Raman frequencies and the lattice vibrational frequencies equally well. The IR spectra of aspirin and its -COOD analogue were simulated by using the calculated normal frequencies and a simple charge flux model.
