Nonlocal free-energy density functional for a broad range of warm dense matter simulations

Due to the favorable linear scaling with system size, irrespective of temperatures, finite-temperature orbital-free density functional theory (FT-OFDFT) holds considerable promise for investigating the properties of warm dense matter. However, the quality of FT-OFDFT strongly depends on a noninteracting free-energy-density functional. The authors derived a nonlocal free-energy functional named XWMF using line integrals. XWMF exhibits high numerical accuracy and stability, enabling FT-OFDFT for realistic simulations of the warm dense matter across a broad range of temperatures and pressures.