Hybrid density functional-molecular mechanics calculations for core-electron binding energies of glycine in water solution.
Hybrid density functional-molecular mechanics calculations for core-electron binding energies of glycine in water solution.
复制标题
水溶液中甘氨酸核心电子结合能的混合密度功能分子力学计算。
DOI：
10.1039/c2cp43264a
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
H. Ågren
中科院分区：
文献类型：
--
作者：
J. Niskanen;N. Arul Murugan;Ž. Rinkevičius;O. Vahtras;Cui Li;S. Monti;Vincenzo Carravetta;H. Ågren
我们报告了对不同 pH 值水溶液中的甘氨酸进行的混合密度泛函理论-分子力学 (DFT/MM) 计算。在本文中，我们讨论了量子力学-分子力学 (QM/MM) 模拟的几个方面，其中依次计算动力学和光谱结合能位移，并通过分子或 Car-Parrinello 动力学模拟生成的一组配置来评估后者。在所使用的模型中，核心电离发生在甘氨酸中，作为用 DFT 建模的量子力学 (QM) 系统，并且用大分子力学 (MM) 体积的水分子中的有利力场来描述溶液。考虑了两个（DFT 和 MM）部分内部和之间的所有相互作用对核心电子结合能的贡献，电荷转移和色散除外。虽然所得结果与实验定性一致，但其精度必须满足反离子、电荷转移以及系统 QM 和 MM 部分的优化划分问题。结果与最近的一项研究进行了比较 [Ottoson 等人，J. Am.化学。社会学会，2011，133，3120]。
We report hybrid density functional theory-molecular mechanics (DFT/MM) calculations performed for glycine in water solution at different pH values. In this paper, we discuss several aspects of the quantum mechanics-molecular mechanics (QM/MM) simulations where the dynamics and spectral binding energy shifts are computed sequentially, and where the latter are evaluated over a set of configurations generated by molecular or Car-Parrinello dynamics simulations. In the used model, core ionization takes place in glycine as a quantum mechanical (QM) system modeled with DFT, and the solution is described with expedient force fields in a large molecular mechanical (MM) volume of water molecules. The contribution to the core electronic binding energy from all interactions within and between the two (DFT and MM) parts is accounted for, except charge transfer and dispersion. While the obtained results were found to be in qualitative agreement with experiment, their precision must be qualified with respect to the problem of counter ions, charge transfer and optimal division of QM and MM parts of the system. Results are compared to those of a recent study [Ottoson et al., J. Am. Chem. Soc., 2011, 133, 3120].
影响因子：
3
作者：
CLARK, T;CHANDRASEKHAR, J;SCHLEYER, PV
通讯作者：
SCHLEYER, PV