The FT-IR and FIF-Raman spectra of isonicotinamide (in solid phase) have been recorded in the regions 4000-400 and 4000-70 cm(-1), respectively. The geometry optimizations and vibrational spectrum calculations of isonicotinamide have been carried out at the DFT/B3LYP level with 6-31 + + G(d,p) basis set. With the SQM approach, the force field of isonicotinamide obtained by DFT calculations has been corrected by a set of scaling factors to get a good agreement between observed and calculated wavenumbers. Isonicotinamide interacting with AI(OH)(3) has also been studied by B3LYP/6-31 + + G(d,p) calculations and the SQM results of both molecules have been compared to investigate how the coordination through the ring nitrogen effects the isonicotinamide vibrational wavenumbers. (c) 2004 Elsevier B.V. All rights reserved.