The linear-response contribution to the exchange-correlation energy functional ${\mathit{E}}_{\mathrm{xc}}$[n] of density-functional theory is reconsidered. An alternative form for this functional is suggested that resolves the convergence problems for finite systems inherent in the original form introduced by Hohenberg and Kohn [Phys. Rev. 136B, 864 (1964)]. Within the exchange-only approximation in which the linear response kernel is known exactly and the optimized-potential model serves as a rigorous comparative standard, the present functional is applied to spherical atoms and jellium spheres. Self-consistent results for these systems indicate that this functional might be worth a more detailed examination.

• Received 26 April 1994

DOI:https://doi.org/10.1103/PhysRevA.51.1159