A QM/MM study on the correlation between the polarisations of and electrons in a hydrated benzene
A QM/MM study on the correlation between the polarisations of and electrons in a hydrated benzene
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水合苯极化与电子相关性的 QM/MM 研究
DOI：
10.1080/08927022.2017.1350661
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发表时间：
2017
影响因子：
2.1
通讯作者：
Morita Akihiro
中科院分区：
文献类型：
--
作者：
Suzuoka Daiki;Takahashi Hideaki;Morita Akihiro
在最近的一项工作中，我们通过进行QM/MM-ER模拟，对苯的水合反应进行了自由能分析，其中总的溶剂化自由能被分解为贡献和。是具有固定电子密度的溶质的溶剂化自由能，是由于溶液中电子密度极化而产生的剩余自由能。我们进一步将水溶液中芳香族溶质的电子密度涨落所产生的自由能分解为来自和轨道的贡献。然而，我们注意到，当轨道的极化与轨道的极化严重耦合时，分解将不会得到验证。在本文中，我们通过QM/MM模拟研究了和轨道极化之间的关联矩阵，以评估轨道之间的耦合强度。我们发现，电子密度极化是由HOMO-LUMO区域内轨道间转移引起的极化所主导的。因此，电子的极化很难与轨道的极化耦合，这证明了我们的分解分析是合理的。
In a recent work, we performed free-energy analyses for hydration of benzene by conducting QM/MM-ER simulations, where the total solvation free energy was decomposed into contributions and. is the solvation free energy of the solute with a fixed electron density and is the residual free energy due to the electron density polarisation in solution. We, further, decomposed the free energies due to electron density fluctuations in aromatic solutes in aqueous solutions into contributions from and orbitals. We note, however, that the decompositions will not be validated when the polarisations of orbitals seriously couple with those of orbitals. In this paper, we study a correlation matrix between polarisations of and orbitals through QM/MM simulations to assess the coupling strength among the orbitals. We found that the electron density polarisation is dominated by the polarisation arising from transfers between the orbitals lying in the HOMO–LUMO region. Thus, the polarisation of electrons hardly couples with that from orbitals, which justifies our decomposition analyses.