论文标题
集成密度功能理论中的密度驱动相关性：原子中简单激发的见解
Density driven correlations in ensemble density functional theory: insights from simple excitations in atoms
论文作者
论文摘要
整体密度功能理论将通常的Kohn-Sham机械扩展到涉及地面和激发态的量子状态集合。作者的最新工作[物理学。莱特牧师。 119，243001（2017）; 123，016401（2019）]表明，Hartree交换和相关能量都可以在合奏中获得异常的特征。密度驱动的（DD）相关性（这是一个事实，即Kohn-Sham合奏中的纯净密度不一定会重现相互作用的纯状态的事实 - 就是这样的特征。在这里，我们研究原子（尤其是$ s $ - $ p $和$ s $ - $ s $过渡），并表明DD相关的幅度和行为可能随所涉及状态的轨道角动量的变化而变化很大。通过根据相关的精确条件Kohn-Sham反演构建的DD相关性的近似值获得了此类估计，以及对弱相关系统的合理假设。
Ensemble density functional theory extends the usual Kohn-Sham machinery to quantum state ensembles involving ground- and excited states. Recent work by the authors [Phys. Rev. Lett. 119, 243001 (2017); 123, 016401 (2019)] has shown that both the Hartree-exchange and correlation energies can attain unusual features in ensembles. Density-driven(DD) correlations -- which account for the fact that pure-state densities in Kohn-Sham ensembles do not necessarily reproduce those of interacting pure states -- are one such feature. Here we study atoms (specifically $S$--$P$ and $S$--$S$ transitions) and show that the magnitude and behaviour of DD correlations can vary greatly with the variation of the orbital angular momentum of the involved states. Such estimations are obtained through an approximation for DD correlations built from relevant exact conditions Kohn-Sham inversion, and plausible assumptions for weakly correlated systems.
