Electronic coupling calculations with transition charges, dipoles, and quadrupoles derived from electrostatic potential fitting
Electronic coupling calculations with transition charges, dipoles, and quadrupoles derived from electrostatic potential fitting
复制标题
DOI：
10.1063/1.4902758
复制
发表时间：
2014-12-07
影响因子：
4.4
通讯作者：
Fujimoto, Kazuhiro J.
中科院分区：
文献类型：
--
作者：
Fujimoto, Kazuhiro J.
提出了一种用于电子耦合计算的静电势转移电荷、偶极和四极方法。TrESP方法基于单个分子跃迁密度之间的电子库仑相互作用的经典描述。在原来的TrESP方法中，只有过渡电荷相互作用被认为是电子耦合。在本研究中，TrESP方法扩展到包括过渡偶极子和四极以及过渡电荷的贡献。因此，在ESP拟合过程中采用了自洽跃迁密度。为了检验本方法的准确性，对氦二聚体、甲烷二聚体和乙烯二聚体进行了几次测试计算。结果表明，与原TrESP方法相比，TrESP-CDQ方法对电子耦合的描述有了很大的改进。计算结果还表明，对跃迁密度的自洽处理对电子耦合计算的准确性有很大的贡献。在成功描述电子耦合的基础上，分析了电子耦合的贡献。该分析清楚地表明，过渡电荷相互作用对电子耦合的贡献可以忽略不计。因此，发现跃迁密度的分布强烈地影响跃迁电荷、偶极和四极的大小。该方法有助于分析和理解激发能转移的机理。(C)2014 AIP Publishing LLC.
A transition charge, dipole, and quadrupole from electrostatic potential (TrESP-CDQ) method for electronic coupling calculations is proposed. The TrESP method is based on the classical description of electronic Coulomb interaction between transition densities for individual molecules. In the original TrESP method, only the transition charge interactions were considered as the electronic coupling. In the present study, the TrESP method is extended to include the contributions from the transition dipoles and quadrupoles as well as the transition charges. Hence, the self-consistent transition density is employed in the ESP fitting procedure. To check the accuracy of the present approach, several test calculations are performed to a helium dimer, a methane dimer, and an ethylene dimer. As a result, the TrESP-CDQ method gives a much improved description of the electronic coupling, compared with the original TrESP method. The calculated results also show that the self-consistent treatment to the transition densities contributes significantly to the accuracy of the electronic coupling calculations. Based on the successful description of the electronic coupling, the contributions to the electronic coupling are also analyzed. This analysis clearly shows a negligible contribution of the transition charge interaction to the electronic coupling. Hence, the distribution of the transition density is found to strongly influence the magnitudes of the transition charges, dipoles, and quadrupoles. The present approach is useful for analyzing and understanding the mechanism of excitation-energy transfer. (C) 2014 AIP Publishing LLC.