Chulhai Dhabih V, Jensen Lasse
Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, USA.
Phys Chem Chem Phys. 2016 Aug 3;18(31):21032-9. doi: 10.1039/c6cp00310a.
Subsystem density functional theory (subsystem DFT) is a DFT partitioning method that is exact in principle, but depends on approximations to the kinetic energy density functional (KEDF). One may avoid the use of approximate KEDFs by ensuring that the inter-subsystem molecular orbitals are orthogonal, termed external orthogonality (EO). We present a method that extends a subsystem DFT method, that includes EO, into the time-dependent DFT (TDDFT) regime. This method therefore removes the need for approximations to the kinetic energy potential and kernel, and we show that it can accurately reproduce the supermolecular TDDFT results for weakly and strongly coupled subsystems, and for systems with strongly overlapping densities (where KEDF approximations traditionally fail).
子系统密度泛函理论（子系统DFT）是一种DFT分区方法，原则上是精确的，但依赖于动能密度泛函（KEDF）的近似。通过确保子系统间分子轨道正交（称为外部正交性，EO），可以避免使用近似的KEDF。我们提出了一种方法，将包含EO的子系统DFT方法扩展到时域密度泛函理论（TDDFT）领域。因此，该方法无需对动能势和核进行近似，并且我们表明它可以准确地重现弱耦合和强耦合子系统以及密度强烈重叠系统（传统上KEDF近似在此类系统中失效）的超分子TDDFT结果。
