Accurate description of van der Waals complexes by density functional theory including empirical corrections
Accurate description of van der Waals complexes by density functional theory including empirical corrections
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DOI：
10.1002/jcc.20078
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发表时间：
2004-09-01
影响因子：
3
通讯作者：
Grimme, S
中科院分区：
文献类型：
--
作者：
Grimme, S
一种用密度泛函理论(DFT-D)在实际计算中解释范德华相互作用的经验方法被广泛应用于各种分子络合物。与以前的方案一样，色散能用C6R-6形式的衰减原子间势来描述。使用纯的、梯度校正的密度泛函(BLYP和PBE)，结合库仑算符的恒等式解析(RI)近似，可以非常有效地计算大系统。与以往的工作不同的是，采用了极化TZV或QZV质量的扩展的AO基组，从而将基组叠加误差减小到可以忽略的程度。通过对原子C-6系数使用全局标度因子，可以大大降低结果对函数的依赖性。如果采用陡峭的阻尼函数，则强结合络合物的关联效应的“双重计数”是微不足道的。该方法适用于29个原子和小分子(Ne、CH4、NH3、H2O、CH3F、N-2、F-2、甲酸、乙烯和乙胺)相互之间以及与苯、苯、萘的络合物。芘、冠烯二聚体、萘三聚体、冠烯(.)H2O和四个氢键和堆叠的DNA碱基对(AT和GC)。在几乎所有情况下，结合能和分子间距离的可靠的理论或实验结果都得到了很好的符合。对于堆积的芳香体系和重要的碱基对，DFT-D-BLYP模型似乎甚至优于系统过结合的标准MP2处理。所获得的良好结果表明，该方法是描述化学中许多重要的范德华体系性质的实用工具。此外，DFT-D数据可以用来校准更简单的(例如，力场)势，或者优化的结构可以用作更精确的相互作用能从头计算的输入。(C)2004年威利期刊公司。
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 C6R-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, CH4, NH3, H2O, CH3F, 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 (.) H2O 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. (C) 2004 Wiley Periodicals, Inc.