The generalized energy-based fragmentation approach with an improved fragmentation scheme: benchmark results and illustrative applications.
The generalized energy-based fragmentation approach with an improved fragmentation scheme: benchmark results and illustrative applications.
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DOI：
10.1002/cphc.201200867
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发表时间：
2013-01
期刊：
影响因子：
--
通讯作者：
Shugui Hua;Wei Li;Shuhua Li
中科院分区：
文献类型：
--
作者：
Shugui Hua;Wei Li;Shuhua Li
本文提出了一种改进的基于广义能量碎片化（GEBF）方法的碎片化方案，提高了GEBF方法在总能量计算和分子间相互作用中的准确性。主要的修改是引入一些以两个片段为中心的原语子系统，这些子系统在以前的GEBF实现中被忽略了。数值计算表明，GEBF方法可以提供更精确的基态能量和分子间相互作用。采用M06-2X泛函和cc-pVTZ基集的GEBF方法，研究了与苯乙烯基π共轭分子赝多态性有关的两种二聚体的结构和结合能。比较了不含C-H··F接触的二聚体与相应模型的结合自由能，发现氟原子的取代削弱了由O- h··O氢键形成的二聚体中单体的结合，但增强了由π-π堆叠相互作用形成的二聚体的结合。因此，在这两种二聚体中，C-H···F接触的作用不太显著。
We propose an improved fragmentation scheme for the generalized energy-based fragmentation (GEBF) approach, which improves the accuracy of the GEBF approach in total energy calculations and intermolecular interactions. The main modification is to introduce some two-fragment-centered primitive subsystems, which are neglected in the previous GEBF implementation. Numerical calculations demonstrate that the present GEBF approach can provide more accurate ground-state energies and intermolecular interactions. The present GEBF approach with the M06-2X functional and the cc-pVTZ basis set are employed to investigate the structures and binding energies in two dimeric species, which are related to pseudopolymorphism of a phenyleneethynylene-based π-conjugated molecule. A comparison of the binding free energies in a dimeric species and its corresponding model without C-H···F contacts reveal that the substitution of fluorine atoms weakens the binding of monomers in the dimeric species formed by intermolecular O-H···O hydrogen bonds, but strengthens the binding in the dimer formed by the π-π stacking interaction. Therefore, the C-H···F contacts in these two dimeric species are demonstrated to play a less significant role.