Charge-transfer molecular dynamics simulations of AlN were performed in the microcanonical ensemble with a nonstoichiometric and defective system in order to achieve a realistic representation of the material. Structural properties and the infrared and nuclear magnetic resonance spectra were calculated. The results suggest that the degree of nonstoichiometry and the population of defects may produce considerable effects on the experimental studies using IR and Al-27 NMR techniques. (C) 2002 Elsevier Science B.V. All rights reserved.