Density-functional theory for ensembles of fractionally occupied states. II. Application to the He atom.
Density-functional theory for ensembles of fractionally occupied states. II. Application to the He atom.
复制标题
部分占据态系综的密度泛函理论。
DOI：
--
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
W. Kohn
中科院分区：
文献类型：
--
作者：
L. N. Oliveira;E. Gross;W. Kohn
前一篇论文中提出的计算激发能的两种密度泛函方法，结合最近提出的准局部密度近似的等综交换相关能泛函（W. Kohn, Phys.）。Rev. A 34,737(1986))，应用于He原子。虽然具有不同角动量的近简并能级之间的分裂被严重高估，但在这两种方法中，从电离阈值测量的实验激发能的角动量和自旋平均值都在几个百分点以内得到了再现。讨论了计算出的自洽系综平均密度和与之相关的Kohn-Sham势。
The two density-functional methods of calculating excitation energies proposed in the preceding paper, combined with the recently formulated quasi-local-density approximation for the equiensemble exchange-correlation energy functional (W. Kohn, Phys. Rev. A 34, 737 (1986)), are applied to the He atom. Although the splittings between nearly degenerate levels with different angular momenta are badly overestimated, in both approaches the averages over angular momentum and spin of the experimental excitation energies measured from the ionization threshold are reproduced within a few percent. The computed self-consistent ensemble-averaged densities and the Kohn-Sham potentials associated with them are discussed.