Large-scale compensation of errors in pairwise-additive empirical force fields: comparison of AMBER intermolecular terms with rigorous DFT-SAPT calculations

0347778 - BFÚ 2011 RIV GB eng J - Journal Article
Zgarbová, M. - Otyepka, M. - Šponer, Jiří - Hobza, P. - Jurečka, P.
Large-scale compensation of errors in pairwise-additive empirical force fields: comparison of AMBER intermolecular terms with rigorous DFT-SAPT calculations.
Physical Chemistry Chemical Physics. Roč. 12, č. 35 (2010), s. 10476-10493. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR(CZ) GA203/09/1476
Grant - others:GA MŠk(CZ) LC512; GA MŠk(CZ) GD203/09/H046
Program: LC; GD
Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702
Keywords : amber empirical potential * DFT-SAPT * compensation of errors
Subject RIV: BO - Biophysics
Impact factor: 3.454, year: 2010

The intermolecular interaction energy components for several molecular complexes were calculated using force fields available in the AMBER suite of programs and compared with Density Functional Theory–Symmetry Adapted Perturbation Theory (DFT-SAPT) values. The extent to which such comparison is meaningful is discussed. The comparability is shown to depend strongly on the intermolecular distance, which means that comparisons made at one distance only are of limited value. At large distances the coulombic and van der Waals 1/r6 empirical terms correspond fairly well with the DFT-SAPT electrostatics and dispersion terms, respectively. At the onset of electronic overlap the empirical values deviate from the reference values considerably. However, the errors in the force fields tend to cancel out in a systematic manner at equilibrium distances.
Permanent Link: http://hdl.handle.net/11104/0188476