Kuźniarowicz Piotr, Liu Kai, Aoki Yuriko, Gu Feng Long, Stachowicz Anna, Korchowiec Jacek
Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-Park, Fukuoka, 816-8580, Japan.
J Mol Model. 2014 Jun;20(6):2277. doi: 10.1007/s00894-014-2277-6. Epub 2014 May 31.
A simple way to improve the accuracy of the fragmentation methods is proposed. The formalism was applied to the elongation (ELG) method at restricted open-shell Hartree-Fock (ROHF) level of theory. The α-helix conformer of polyglycine was taken as a model system. The modified ELG method includes a simplified electrostatic field resulting from point-charge distribution of the system's environment. In this way the long-distance polarization is approximately taken into account. The field attenuates during the ELG process to eventually disappear when the final structure is reached. The point-charge distributions for each ELG step are obtained from charge sensitivity analysis (CSA) in force-field atoms resolution. The presence of the intermediate field improves the accuracy of ELG calculations. The errors in total energy and its kinetic and potential contributions are reduced by at least one-order of magnitude. In addition the SCF convergence of ROHF scheme is improved.
提出了一种提高碎片化方法准确性的简单方法。该形式主义应用于受限开壳层哈特里-福克（ROHF）理论水平的伸长（ELG）方法。聚甘氨酸的α-螺旋构象体被用作模型系统。改进的ELG方法包括由系统环境的点电荷分布产生的简化静电场。通过这种方式，近似考虑了长程极化。该场在ELG过程中衰减，在达到最终结构时最终消失。每个ELG步骤的点电荷分布通过力场原子分辨率下的电荷敏感性分析（CSA）获得。中间场的存在提高了ELG计算的准确性。总能量及其动能和势能贡献的误差至少降低了一个数量级。此外，ROHF方案的自洽场收敛性得到了改善。
