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Accurate description of van der Waals complexes by density functional theory including empirical corrections
Author(s) -
Grimme Stefan
Publication year - 2004
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20078
Subject(s) - coronene , van der waals force , density functional theory , chemistry , intermolecular force , scaling , basis set , computational chemistry , trimer , coupled cluster , molecule , thermodynamics , molecular physics , atomic physics , physics , dimer , geometry , mathematics , organic chemistry
An empirical method to account for van der Waals interactions in practical calculations with the density functional theory (termed DFT‐D) is tested for a wide variety of molecular complexes. As in previous schemes, the dispersive energy is described by damped interatomic potentials of the form C 6 R −6 . The use of pure, gradient‐corrected density functionals (BLYP and PBE), together with the resolution‐of‐the‐identity (RI) approximation for the Coulomb operator, allows very efficient computations for large systems. Opposed to previous work, extended AO basis sets of polarized TZV or QZV quality are employed, which reduces the basis set superposition error to a negligible extend. By using a global scaling factor for the atomic C 6 coefficients, the functional dependence of the results could be strongly reduced. The “double counting” of correlation effects for strongly bound complexes is found to be insignificant if steep damping functions are employed. The method is applied to a total of 29 complexes of atoms and small molecules (Ne, CH 4 , NH 3 , H 2 O, CH 3 F, N 2 , F 2 , formic acid, ethene, and ethine) with each other and with benzene, to benzene, naphthalene, pyrene, and coronene dimers, the naphthalene trimer, coronene · H 2 O and four H‐bonded and stacked DNA base pairs (AT and GC). In almost all cases, very good agreement with reliable theoretical or experimental results for binding energies and intermolecular distances is obtained. For stacked aromatic systems and the important base pairs, the DFT‐D‐BLYP model seems to be even superior to standard MP2 treatments that systematically overbind. The good results obtained suggest the approach as a practical tool to describe the properties of many important van der Waals systems in chemistry. Furthermore, the DFT‐D data may either be used to calibrate much simpler (e.g., force‐field) potentials or the optimized structures can be used as input for more accurate ab initio calculations of the interaction energies. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1463–1473, 2004