학술논문

Effective yet reliable computation of hyperfine coupling constants in solution by a QM/MM approach: Interplay between electrostatics and non-electrostatic effects.
Document Type
Article
Source
Journal of Chemical Physics. 3/28/2019, Vol. 150 Issue 12, pN.PAG-N.PAG. 13p. 2 Diagrams, 6 Charts, 6 Graphs.
Subject
*HYPERFINE coupling
*COUPLING constants
*NITROXIDES
*MOLECULAR spectra
*AQUEOUS solutions
*ELECTROSTATICS
Language
ISSN
0021-9606
Abstract
In this paper, we have extended to the calculation of hyperfine coupling constants, the model recently proposed by some of the present authors [Giovannini et al., J. Chem. Theory Comput. 13, 4854–4870 (2017)] to include Pauli repulsion and dispersion effects in Quantum Mechanical/Molecular Mechanics (QM/MM) approaches. The peculiarity of the proposed approach stands in the fact that repulsion/dispersion contributions are explicitly introduced in the QM Hamiltonian. Therefore, such terms not only enter the evaluation of energetic properties but also propagate to molecular properties and spectra. A novel parametrization of the electrostatic fluctuating charge force field has been developed, thus allowing a quantitative reproduction of reference QM interaction energies. Such a parametrization has been then tested against the prediction of EPR parameters of prototypical nitroxide radicals in aqueous solutions. [ABSTRACT FROM AUTHOR]