Performance and basis set dependence of density functional theory dipole and quadrupole moments

A study is presented concerning the performance and basis set dependence of density functional methods in the calculation of dipole and quadrupole mom ents. A set of some small molecules was thereby used, together with seven c ommonly used exchange correlation functionals and Dunnings correlation cons istent aug-cc-pVDZ, aug-cc-pVTZ, aug-cc-pVQZ and aug-cc-pV5Z basis sets. Th e results were compared with experiment and previously published values obt ained with traditional ab initio molecular orbital methods. The best perfor mance in the calculation of dipole and quadrupole moments is due to the hyb rid functionals B3LYP and B3PW91. Moreover, the results seem to be essentia lly converged at the aug-cc-pVTZ level. Comparison of the LDA/aug-cc-pV5Z r esults with the numerical LDA results of Dickson and Becke, reveals that bo th sets of values are identical for most cases. (C) 2000 Elsevier Science B .V. All rights reserved.