Is the spin-orbit coupling important in the prediction of the 51V hyperfine coupling constants of VIVO2+ species? ORCA versus Gaussian performance and biological applications

Abstract

Density functional theory calculations of the 51V hyperfine coupling (HFC) tensor A, have been completed for eighteen VIVO 2+ complexes with different donor set, electric charge and coordination geometry. A tensor was calculated with ORCA software with several functionals and basis sets taking into account the spin-orbit coupling contribution. The results were compared with those obtained with Gaussian 03 software using the half-and-half functional BHandHLYP and 6-311g(d,p) basis set. The order of accuracy of the functionals in the prediction of Aiso, Az and dipolar term Az,anis is BHandHLYP > PBE0 >> B3PW > TPSSh >> B3LYP >> BP86 > VWN5 (for A iso), BHandHLYP > PBE0 >> B3PW > TPSSh > B3LYP >> BP86 > VWN5 (for Az), B3LYP > PBE0 ∼ B3PW ∼ BHandHLYP >> TPSSh > BP86 ∼ VWN5 (for Az,anis). The good agreement in the prediction of Az with BHandHLYP is due to a compensation between the overestimation of Aiso and underestimation of Az,anis (Az = Aiso + Az,anis), whereas among the hybrid functionals PBE0 performs better than the other ones. BHandHLYP functional and Gaussian software are recommended when the V IVO2+ species contains only V-O and/or V-N bonds, whereas PBE0 functional and ORCA software for VIVO2+ complexes with one or more V-S bonds. Finally, the application of these methods to the coordination environment of VIVO2+ ion in V-proteins, like vanadyl-substituted insulin, carbonic anhydrase, collagen and S-adenosylmethionine synthetase, was discussed. Copyright © 2011 Wiley Periodicals, Inc.