Max Planck Institute for the Structure and Dynamics of Matter , 22761 Hamburg , Germany.
Center for Computational Quantum Physics (CCQ) , Flatiron Institute , 162 Fifth Avenue , New York , New York 10010 , United States.
J Chem Theory Comput. 2019 Oct 8;15(10):5209-5220. doi: 10.1021/acs.jctc.9b00063. Epub 2019 Sep 20.
In the present work, we introduce a self-consistent density-functional embedding technique, which leaves the realm of standard energy-functional approaches in density functional theory and targets directly the density-to-potential mapping that lies at its heart. Inspired by the density matrix embedding theory, we project the full system onto a set of small interacting fragments that can be solved accurately. Based on the rigorous relation of density and potential in density functional theory, we then invert the fragment densities to local potentials. Combining these results in a continuous manner provides an update for the Kohn-Sham potential of the full system, which is then used to update the projection. We benchmark our approach for molecular bond stretching in one and two dimensions and show that, in these cases, the scheme converges to accurate approximations for densities and Kohn-Sham potentials. We demonstrate that the known steps and peaks of the exact exchange-correlation potential are reproduced by our method with remarkable accuracy.
在本工作中，我们引入了一种自洽密度泛函嵌入技术，该技术脱离了密度泛函理论中标准能量泛函方法的范畴，直接针对其核心的密度到势能映射。受密度矩阵嵌入理论的启发，我们将整个系统投影到一组可以精确求解的小相互作用片段上。基于密度泛函理论中密度和势能的严格关系，我们反演片段密度以得到局部势能。以连续的方式组合这些结果，为整个系统的 Kohn-Sham 势能提供了更新，然后使用该更新来投影。我们对一维和二维的分子键拉伸进行了基准测试，结果表明，在这些情况下，该方案可以收敛到密度和 Kohn-Sham 势能的精确近似。我们证明了我们的方法可以非常准确地再现精确交换相关势能的已知阶数和峰。
