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 te chniques employing the Becke-Perdew-86 gradient corrected exchange correlat ion functional. A large number of singlet and triplet stationary points rep resenting local minima and transition structures of (AIN), are completely c haracterised. We report energies, equilibrium geometric parameters, selecte d harmonic vibrational wave numbers along with corresponding absorption coe fficients. Stability and geometric aspects of (AIN)12 are discussed in deta il by introducing a measure of sphericity. (C) 2001 Elsevier Science B.V. A ll rights reserved.