Abstract
The Dirac exchange energy has a density in a spherically symmetric ten-electron atomic ion that is determined by the idempotent first-order density matrix (1 DM). In turn, this 1 DM has as its leading term in the expansion, with Z the atomic number, the bare Coulomb result. This latter quantity is known analytically from the study of March and Santamaria [Phys. Rev. A 38, 5002 (1988)]. Here is calculated analytically, and presented graphically for in this large-Z limit. The Slater approximation to the exchange potential namely, with the ground-state electron density, is also plotted for In the large-Z limit, can be obtained by functional differentiation of the resultant exchange energy, and is expressed in terms of electron and kinetic-energy densities. Numerical calculations, based on plus approximate corrections, are also presented.
- Received 23 June 2000
DOI:https://doi.org/10.1103/PhysRevA.62.062512
©2000 American Physical Society