Browsing by Author "Rossikhin, V. V."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Accurate Calculations of Second-Order Electric and Magnetic Properties: Two Ways of Physically Justified Modifications of Basis Sets
    (Elsevier B.V., 2010) Bolshakov, V.; Rossikhin, V. V.; Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Okovytyy, Sergiy I.; Leszczynski, Jerzy
    EN: Second-order electric and magnetic properties calculated using an approach based upon the simultaneous analytical dependence of the bond order matrix and basis set functions on the corresponding perturbation parameters have been obtained and analyzed for a series of organic molecules. Various methods of selection of basis set quality for different atoms in investigated molecules were examined in conjunction with calculations of 1H NMR chemical shifts. Comparison of the results obtained at different levels of theory (HF, DFT, MP2) demonstrates small correlation effects for polarizability and magnetic susceptibility while the electron correlation effects play crucial role for calculations of nuclear magnetic shielding (chemical shifts).
  • Thumbnail Image
    Item
    Novel Physically Adapted STO##-3G Basis Sets. Efficiency for Prediction of Second-Order Electric and Magnetic Properties of Aromatic Hydrocarbons
    (John Wiley & Sons, Inc., 2012) Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Rossikhin, V. V.; Okovytyy, Sergiy I.; Shatckih, A.; Bolshakov, V.; Leszczynski, Jerzy
    EN: Efficient scheme for construction of physically justified STO##-3Gel and STO##-3Gmag basis sets has been proposed. It is based upon the analysis of analytical form of the first-order correction functions to unperturbed STO basis sets under the perturbation by electric or magnetic fields. The test calculations of polarizability, magnetic susceptibility and chemical shifts performed for a series of aromatic compounds within the developed basis set in the framework of Hartree-Fock and Density Functional Theory (DFT) approaches show good agreement of the predicted properties with experiments.