title: Is the spin-orbit coupling important in the prediction of the 51V hyperfine coupling constants of V(IV) O2+ species? ORCA versus Gaussian performance and biological applications.
abstract: Density functional theory calculations of the (51)V hyperfine coupling (HFC) tensor A, have been completed for eighteen V(IV)O(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 A(iso), A(z) and dipolar term A(z,anis) is BHandHLYP > PBE0 >> B3PW > TPSSh >> B3LYP >> BP86 > VWN5 (for A(iso)), BHandHLYP > PBE0 >> B3PW > TPSSh > B3LYP >> BP86 > VWN5 (for A(z)), B3LYP > PBE0 ∼ B3PW ∼ BHandHLYP >> TPSSh > BP86 ∼ VWN5 (for A(z,anis)). The good agreement in the prediction of A(z) with BHandHLYP is due to a compensation between the overestimation of A(iso) and underestimation of A(z,anis) (A(z) = A(iso) + A(z,anis)), whereas among the hybrid functionals PBE0 performs better than the other ones. BHandHLYP functional and Gaussian software are recommended when the V(IV)O(2+) species contains only V-O and/or V-N bonds, whereas PBE0 functional and ORCA software for V(IV)O(2+) complexes with one or more V-S bonds. Finally, the application of these methods to the coordination environment of V(IV)O(2+) ion in V-proteins, like vanadyl-substituted insulin, carbonic anhydrase, collagen and S-adenosylmethionine synthetase, was discussed.
authors: Dipartimento di Chimica e Centro Interdisciplinare per lo Sviluppo della Ricerca Biotecnologica e per lo Studio della Biodiversità della Sardegna, Università di Sassari, Via Vienna 2, I-07100 Sassari, Italy.
authors: Giovanni
authors: G
authors: Micera
authors: Eugenio
authors: E
authors: Garribba
mesh_terms: D000818:Animals; D002256:Carbonic Anhydrases / Q000737:chemistry; D002413:Cations, Divalent / Q000737:chemistry; D003094:Collagen / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000737:chemistry; D008716:Methionine Adenosyltransferase / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D011789:Quantum Theory; D014639:Vanadium / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D007328:Insulin; D011506:Proteins; D014639:Vanadium; D003094:Collagen; D008716:Methionine Adenosyltransferase; D002256:Carbonic Anhydrases; D010100:Oxygen