Nonlocal energy-optimized kernel: Recovering second-order exchange in the homogeneous electron gas

Article

关键词: DENSITY-FUNCTIONAL THEORY;    RANDOM-PHASE-APPROXIMATION;    METALLIC SURFACE;    BEHAVIOR;    SYSTEMS;    FORCES;   

DOI  :  10.1103/PhysRevB.93.045119

来源: SCIE

【 摘 要 】

In order to remedy some of the shortcomings of the random phase approximation (RPA) within adiabatic connection fluctuation-dissipation (ACFD) density functional theory, we introduce a short-ranged, exchange-like kernel that is one-electron self-correlation free and exact for two-electron systems in the high-density limit. By tuning a free parameter in our model to recover an exact limit of the homogeneous electron gas correlation energy, we obtain a nonlocal, energy-optimized kernel that reduces the errors of RPA for both homogeneous and inhomogeneous solids. Using wave-vector symmetrization for the kernel, we also implement RPA renormalized perturbation theory for extended systems, and demonstrate its capability to describe the dominant correlation effects with a low-order expansion in both metallic and nonmetallic systems. The comparison of ACFD structural properties with experiment is also shown to be limited by the choice of norm-conserving pseudopotential.

【 授权许可】

Free