%0 Journal Article
%T <br>
%A 何禹
%A 王一波
%J 物理化学学报
%D 2016
%R 10.3866/PKU.WHXB201609132
%X APF密度泛函色散校正（APF-D）是由B3PW91和PBE0杂化的APF泛函，加上球形原子模型（SAM）色散校正构成的一种有别于Grimme经验色散校正的密度泛函理论色散校正（DFT-D）方法，计算稀有气体及其与小分子复合物结合能和势能面准确性很高，但对常见氢键、C―H…π和π…π等复合物结合能计算结果明显偏大，在一般性分子间相互作用问题研究中一直未被认可和采纳。我们发现APF-D结合能计算结果偏大的原因是APF泛函与SAM色散校正重复计入了一定量的长程色散能；通过引入不依赖于体系的SAM色散能阻力因子ζ，简单而有效地解决了APF-D色散能过度补偿问题，提出了APF-D改进方案APF-D*；通过S66和L7标准测试集的对照计算表明，APF-D*结合能准确性远高于原始APF-D，达到和超过目前常用的B3LYPD3和ωB97X-D方法水平，并具有较好的计算效率，期待在大体系分子间相互作用研究中得到广泛应用。<br>Austin-Petersson-Frisch (APF) is a new hybrid density functional method that combines B3PW91 and PBE0. APF-D provides an additional empirical dispersion correction method based on a spherical atom model (SAM), which is different from the Grimme's empirical dispersion correction method. APF-D accurately describes the binding energy and the potential energy surfaces of complexes of noble gas atoms and small hydrocarbon dimers. However, APF-D is not accepted as a standard method to study intermolecular interactions because the results often show a large deviation from the normal range when using the APF-D method to calculate the binding energy of hydrogen bonded complexes, C-H…π and π…π interactions. Our research identified that such a deviation arises from some long-range dispersion that has been double counted by the APF function and the SAM dispersion correction. Therefore, we propose an improved APF-D method, termed APF-D*. By taking advantage of ζ, which is independent of SAM dispersion, we were able to solve effectively the problem of excessive dispersion compensation in APF-D. By comparing the results from S66 and L7 benchmark sets, we find that APF-D* greatly improved the precision of calculations over the traditional APF-D method. The overall accuracy of APF-D* was found to be comparable to or better than current leading DFT methods, such as B3LYP-D3 and ωB97X-D. However, both B3LYP-D3 and ωB97X-D have a much larger computational cost than APF-D*. We believe that APF-D* is a better method to calculate of the intermolecular energy of large molecules
%U http://www.whxb.pku.edu.cn/CN/Y2016/V32/I11/2709