Accuracy of the three-body fragment molecular orbital method applied to Moller-Plesset perturbation theory

作者：Fedorov Dmitri G^*; Ishimura Kazuya; Ishida Toyokazu; Kitaura Kazuo; Pulay Peter; Nagase Shigeru

来源：Journal of Computational Chemistry, 2007, 28(9): 1476-1484.

DOI：10.1002/jcc.20645

• fragment molecular orbital
• Moller-Plesset
• GAMESS
• parallel
• GDDI
• protein
• polypeptide

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.

• 出版日期2007-7-15