Phillips Heidi, Geva Eitan, Dunietz Barry D
Department of Chemistry, University of Michigan , Ann Arbor, Michigan, United States.
J Chem Theory Comput. 2012 Aug 14;8(8):2661-8. doi: 10.1021/ct300318g. Epub 2012 Jul 6.
Time-dependent density functional theory with range-separated hybrid functionals is used to calculate off-site excitations involving transitions between spatially separated orbitals in weakly coupled systems. Although such off-site excitations involve charge transfer, orbital degeneracy in symmetrical systems results in linear combinations of off-site excitations with equal weights and therefore zero net charge-transfer character. Like other types of off-site excitations, such "hidden" charge-transfer excitations are not accurately captured by conventional density functionals. We show that the recently introduced Baer-Neuhauser-Livshitz range-separated hybrid functional accurately characterizes such hidden off-site excitation energies via applications to the ethene dimer model system and to dye-functionalized silsesquioxanes.
采用含范围分离杂化泛函的含时密度泛函理论来计算弱耦合体系中涉及空间分离轨道间跃迁的非原位激发。尽管这种非原位激发涉及电荷转移，但对称体系中的轨道简并会导致具有相等权重的非原位激发的线性组合，从而净电荷转移特征为零。与其他类型的非原位激发一样，传统密度泛函无法准确捕捉这种“隐藏”的电荷转移激发。我们表明，最近引入的Baer-Neuhauser-Livshitz范围分离杂化泛函通过应用于乙烯二聚体模型体系和染料功能化倍半硅氧烷，能够准确地表征这种隐藏的非原位激发能。
