title: Evaluation of the SCF Combination of KS-DFT and 3D-RISM-KH; Solvation Effect on Conformational Equilibria, Tautomerization Energies, and Activation Barriers.
abstract: The effect of solvation on conformational equilibria, tautomerization energies, and activation barriers in simple SN2 reactions is reproduced by using the self-consistent field coupling of the Kohn-Sham density functional theory (KS-DFT) for electronic structure and the three-dimensional reference interaction site model with the closure approximation of Kovalenko and Hirata (3D-RISM-KH) for molecular solvation structure. These examples are used in order to validate the implementation of the 3D-RISM-KH method in the Amsterdam Density Functional package. The computations of the free energy difference in the trans/gauche conformational equilibrium for 1,2-dichloroethane in different solvents; the relative tautomerization free energy for cytosine, isocytosine, and guanine; and the free energy activation barrier for a CH3X-type (X = F, Cl, Br) SN2 reaction exhibit agreement with the experimental data. The method is also applied to the electronic and hydration structure of carbon single-wall nanotubes of different diameters, including the effect of water located in the inner space of the nanotubes. A comparison with continuum models of solvation (including COSMO) as well as with other more precise and computationally more expensive calculations is made to demonstrate the accuracy and predictive capability of the new KS-DFT/3D-RISM-KH method.
authors.affiliation: Departament de Química Inorgànica and Centre de Recerca en Química Teòrica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, National Institute for Nanotechnology, National Research Council of Canada, 421 Saskatchewan Drive, Edmonton, Alberta, T6G 2M9, Canada, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada, and Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Casanova
authors.affiliation: Departament de Química Inorgànica and Centre de Recerca en Química Teòrica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, National Institute for Nanotechnology, National Research Council of Canada, 421 Saskatchewan Drive, Edmonton, Alberta, T6G 2M9, Canada, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada, and Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
authors.forename: Sergey
authors.initials: S
authors.lastname: Gusarov
authors.affiliation: Departament de Química Inorgànica and Centre de Recerca en Química Teòrica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, National Institute for Nanotechnology, National Research Council of Canada, 421 Saskatchewan Drive, Edmonton, Alberta, T6G 2M9, Canada, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada, and Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
authors.forename: Andriy
authors.initials: A
authors.lastname: Kovalenko
authors.affiliation: Departament de Química Inorgànica and Centre de Recerca en Química Teòrica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, National Institute for Nanotechnology, National Research Council of Canada, 421 Saskatchewan Drive, Edmonton, Alberta, T6G 2M9, Canada, Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada, and Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
authors.forename: Tom
authors.initials: T
authors.lastname: Ziegler