The IR and Raman spectra of buspirone and buspirone hydrochloride were recorded in KBr pellets and chloroform solutions. Most of the vibrational bands were assigned to normal modes using quantum mechanical semiempirical and ab initio restricted Hartree-Fock (RHF) calculations on model systems. The essential spectral characteristics can be obtained from the analysis of three building blocks of buspirone, ie pyrimidine-piperazine, butyl spacer ...