Generalization of the Gaussian electrostatic model: Extension to arbitrary angular momentum, distributed multipoles, and speedup with reciprocal space methods
Generalization of the Gaussian electrostatic model: Extension to arbitrary angular momentum, distributed multipoles, and speedup with reciprocal space methods
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DOI：
10.1063/1.2363374
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发表时间：
2006-11-14
影响因子：
4.4
通讯作者：
Darden, Thomas A.
中科院分区：
文献类型：
--
作者：
Cisneros, G. Andres;Piquemal, Jean-Philip;Darden, Thomas A.
通过当前的经验力场模拟生物系统由于缺乏准确性而存在缺陷，特别是在非键项的描述方面。我们之前介绍过基于密度拟合的力场，称为高斯静电模型-0 (GEM-0) J.-P。皮克马尔[J.化学。物理。 124, 104101 (2006)] 改进了非键相互作用的描述。 GEM-0 依靠密度拟合方法，通过扩展以特定位点为中心的 s 型高斯函数中分子的电子密度，来重现约束空间轨道变分 (CSOV) 能量分解方案的每个贡献。在本贡献中，我们将力场的库仑分量和交换分量扩展到任意角动量的辅助基组。由于具有较高角动量的基函数具有方向性，因此采用参考分子框架（局部框架）形式来旋转拟合展开系数。在所有情况下，分子间相互作用能都是使用 McMurchie-Davidson [J.计算。物理。 26, 218 (1978)]递归计算所有所需的积分。此外，埃尔米特高斯函数的使用允许在每个扩展位置处进行点多极分解确定。此外，还通过基于倒易空间的形式研究了计算速度问题，其中包括粒子网格 Ewald (PME) 和快速傅立叶泊松 (FFP) 方法。给出了水二聚体势能表面上十个固定点的冻结核心（库仑和交换排斥）分子间相互作用结果，以及典型水二聚体、甲酰胺、堆叠苯和苯水二聚体的一维表面扫描。所有结果均与相应 CSOV 计算的参考贡献相当一致，库仑和交换误差分别约为 0.1 和 0.15 kcal/mol。还提供了 (H2O)(n)、n=64、128、256、512 和 1024 的单库仑能量力计算的计时结果，在 PME 和 FFP 的周期性边界条件下，在两种不同的 rms 力容差下。对于小型和中型辅助设备，PME 在精度和精度方面都比 FFP 表现出更快的时间，并且 PME 的优势在更高的精度下扩大，而对于最大的辅助设备，情况恰恰相反。
The simulation of biological systems by means of current empirical force fields presents shortcomings due to their lack of accuracy, especially in the description of the nonbonded terms. We have previously introduced a force field based on density fitting termed the Gaussian electrostatic model-0 (GEM-0) J.-P. Piquemal [J. Chem. Phys. 124, 104101 (2006)] that improves the description of the nonbonded interactions. GEM-0 relies on density fitting methodology to reproduce each contribution of the constrained space orbital variation (CSOV) energy decomposition scheme, by expanding the electronic density of the molecule in s-type Gaussian functions centered at specific sites. In the present contribution we extend the Coulomb and exchange components of the force field to auxiliary basis sets of arbitrary angular momentum. Since the basis functions with higher angular momentum have directionality, a reference molecular frame (local frame) formalism is employed for the rotation of the fitted expansion coefficients. In all cases the intermolecular interaction energies are calculated by means of Hermite Gaussian functions using the McMurchie-Davidson [J. Comput. Phys. 26, 218 (1978)] recursion to calculate all the required integrals. Furthermore, the use of Hermite Gaussian functions allows a point multipole decomposition determination at each expansion site. Additionally, the issue of computational speed is investigated by reciprocal space based formalisms which include the particle mesh Ewald (PME) and fast Fourier-Poisson (FFP) methods. Frozen-core (Coulomb and exchange-repulsion) intermolecular interaction results for ten stationary points on the water dimer potential-energy surface, as well as a one-dimensional surface scan for the canonical water dimer, formamide, stacked benzene, and benzene water dimers, are presented. All results show reasonable agreement with the corresponding CSOV calculated reference contributions, around 0.1 and 0.15 kcal/mol error for Coulomb and exchange, respectively. Timing results for single Coulomb energy-force calculations for (H2O)(n), n=64, 128, 256, 512, and 1024, in periodic boundary conditions with PME and FFP at two different rms force tolerances are also presented. For the small and intermediate auxiliaries, PME shows faster times than FFP at both accuracies and the advantage of PME widens at higher accuracy, while for the largest auxiliary, the opposite occurs.