Liu Kai, Korchowiec Jacek, Aoki Yuriko
Department of Material Sciences, Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga Park, Fukuoka 816-8580 (Japan).
K. Gumiński Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Kraków (Poland).
Chemphyschem. 2015 May 18;16(7):1551-6. doi: 10.1002/cphc.201402901. Epub 2015 Mar 12.
An intermediate electrostatic field is introduced to improve the accuracy of fragment-based quantum-chemical computational methods by including long-range polarizations of biomolecules. The point charge distribution of the intermediate field is generated by a charge sensitivity analysis that is parameterized for five different population analyses, namely, atoms-in-molecules, Hirshfeld, Mulliken, natural orbital, and Voronoi population analysis. Two model systems are chosen to demonstrate the performance of the generalized elongation method (ELG) combined with the intermediate electrostatic field. The calculations are performed for the STO-3G, 6-31G, and 6-31G(d) basis sets and compared with reference Hartree-Fock calculations. It is shown that the error in the total energy is reduced by one order of magnitude, independently of the population analyses used. This demonstrates the importance of long-range polarization in electronic-structure calculations by fragmentation techniques.
