Gould Tim
Qld Micro- and Nano-technology Centre, Griffith University, Nathan, Qld 4111, Australia.
J Phys Chem Lett. 2020 Nov 19;11(22):9907-9912. doi: 10.1021/acs.jpclett.0c02894. Epub 2020 Nov 10.
Recent theory developments in ensemble density functional theory (EDFT) promise to bring decades of work for ground states to the practical resolution of excited states, provided newly discovered "density-driven correlations" can be dealt with and adequate effective potentials can be found. This Letter introduces simple theories for both and shows that EDFT using these theories outperforms ΔSCF DFT and time-dependent DFT for low-lying gaps in most of the small atoms and molecules tested, even when all use the same density functional approximations. It thus establishes EDFT as a promising tool for low-cost studies of low-lying excited states and provides a clear route to practical EDFT implementation of arbitrary functional approximations.
最近，在系综密度泛函理论（EDFT）方面的理论进展有望将几十年来关于基态的研究成果应用于激发态的实际求解，前提是新发现的“密度驱动关联”能够得到处理，并且能够找到合适的有效势。本信函介绍了这两方面的简单理论，并表明使用这些理论的EDFT在大多数测试的小原子和分子中，对于低能隙的计算优于ΔSCF DFT和含时DFT，即使所有方法都使用相同的密度泛函近似。因此，它确立了EDFT作为一种有前途的工具，可用于低成本的低激发态研究，并为任意泛函近似的实际EDFT实现提供了一条清晰的途径。
