A density functional study of small (AlN)x clusters:: structures, energies, and frequencies

Structural properties of energetically low-lying stationary points of small aluminium/nitrogen clusters with unity stoichiometric ratio (AlN)(x) (x = 1, 2, 4, 6, 12) have been investigated by theoretical density functional techniques employing the Becke-Perdew-86 gradient corrected exchange correlation functional. A large number of singlet and triplet stationary points representing local minima and transition structures of (AIN), are completely characterised. We report energies, equilibrium geometric parameters, selected harmonic vibrational wave numbers along with corresponding absorption coefficients. Stability and geometric aspects of (AIN)12 are discussed in detail by introducing a measure of sphericity. (C) 2001 Elsevier Science B.V. All rights reserved.