Abstract
Within density functional theory, a coordinate-scaling relation for the coupling-constant dependence of the exchange-correlation kernel is utilized to express the correlation energy of a many-electron system in terms of As a test of several of the available approximations for the exchange-correlation kernel, or equivalently the local-field factor, we calculate the uniform-gas correlation energy. While the random phase approximation 0) makes the correlation energy per electron too negative by about 0.5 eV, the adiabatic local-density approximation 0)] makes a comparable error in the opposite direction. The adiabatic nonlocal approximation 0)] reduces this error to about 0.1 eV, and inclusion of the full frequency dependence in an approximate parametrization reduces it further to less than 0.02 eV. We also report the wave-vector analysis and the imaginary-frequency analysis of the correlation energy for each choice of kernel.
- Received 11 November 1999
DOI:https://doi.org/10.1103/PhysRevB.61.13431
©2000 American Physical Society