Yang Zeng-Hui, Pribram-Jones Aurora, Burke Kieron, Ullrich Carsten A
Microsystem and Terahertz Research Center, China Academy of Engineering Physics, Chengdu 610200, China.
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Phys Rev Lett. 2017 Jul 21;119(3):033003. doi: 10.1103/PhysRevLett.119.033003.
A very specific ensemble of ground and excited states is shown to yield an exact formula for any excitation energy as a simple correction to the energy difference between orbitals of the Kohn-Sham ground state. This alternative scheme avoids either the need to calculate many unoccupied levels as in time-dependent density functional theory (TDDFT) or the need for many self-consistent ensemble calculations. The symmetry-eigenstate Hartree-exchange (SEHX) approximation yields results comparable to standard TDDFT for atoms. With this formalism, SEHX yields approximate double excitations, which are missed by adiabatic TDDFT.
一个非常特殊的基态和激发态组合被证明可以给出任何激发能的精确公式，该公式是对Kohn-Sham基态轨道能量差的简单修正。这种替代方案避免了像含时密度泛函理论（TDDFT）那样计算许多未占据能级的需求，也避免了进行许多自洽系综计算的需求。对称本征态哈特里交换（SEHX）近似对于原子给出的结果与标准TDDFT相当。利用这种形式体系，SEHX产生了绝热TDDFT所遗漏的近似双激发。
