Accuracy of the three-body fragment molecular orbital method applied to Moller-Plesset perturbation theory
Accuracy of the three-body fragment molecular orbital method applied to Moller-Plesset perturbation theory
复制标题
DOI：
10.1002/jcc.20645
复制
发表时间：
2007-07-15
影响因子：
3
通讯作者：
Nagase, Shigeru
中科院分区：
文献类型：
--
作者：
Fedorov, Dmitri G.;Ishimura, Kazuya;Nagase, Shigeru
将碎片分子轨道方法（FMO）中的三体能量展开应用于二级Moller-Plesset理论（MP2）。使用6- 31 G * 和6- 311 G * 基组，针对水团簇、丙氨酸n-mer（α-螺旋和β-链）和一种合成蛋白质确定了两体和三体展开的准确性。在最好的理论水平（三体，每个片段两个分子/残基），能量相对于从头MP2的绝对误差最多为1.2和5.0 martree，分别为6- 31 G * 和6- 311 G * 基组。6- 31 G * 和6- 311 G * 的相对准确度最差分别为99.996%和99.96%。引入三体近似，确定了最佳阈值。在生产水平（FMO 2/2）的蛋白质计算（6- 31 G *）在36个3.2-GHz Pentium 4节点上花费3小时，并且MP2相关能量的绝对误差仅为2 kcal/mol。(C)2007 Wiley Periodicals，Inc.
The three-body energy expansion in the fragment molecular orbital method (FMO) was applied to the 2nd order Moller-Plesset theory (MP2). The accuracy of both the two and three-body expansions was determined for water clusters, alanine n-mers (alpha-helices and beta-strands) and one synthetic protein, using the 6-31G* and 6-311G* basis sets. At the best level of theory (three-body, two molecules/residues per fragment), the absolute errors in energy relative to ab initio MP2 were at most 1.2 and 5.0 mhartree, for the 6-31G* and 6-311G* basis sets, respectively. The relative accuracy was at worst 99.996% and 99.96%, for 6-31G* and 6-311G*, respectively. A three-body approximation was introduced and the optimum threshold value was determined. The protein calculation (6-31G*) at the production level (FMO2/2) took 3 h on 36 3.2-GHz Pentium 4 nodes and had the absolute error in the MP2 correlation energy of only 2 kcal/mol. (C) 2007 Wiley Periodicals, Inc.