Studies on tautomerism in tetrazole: comparison of Hartree-Fock and density functional theory quantum chemical methods

A comparison of the ab initio quantum chemical methods: Hartree-Fock (HF) and hybrid density functional theory (DFT)/B3LYP for the treatment of tautomeric equilibria both in the gas phase and in the solution is made. The solvent effects were investigated in terms of the self-consistent reaction field (SCRF). Ionization potentials (IP), calculated by DFT/B3LYP, are also compared with those calculated previously within the HF frame. (C) 2000 Elsevier Science B.V. All rights reserved.