Path integral Monte Carlo simulations of warm dense sodium

High energy density physics and astrophysics require reliable methods for determining the equation of state of warm dense matter. At high temperatures (above 106 K or 100 eV), path integral Monte Carlo (PIMC) as a first-principles method is a useful option because of its accuracy and efficiency. Previous developments in PIMC implemented free-particle nodes to study plasmas comprised of heavy (Z ≤ 10) elements and constructed equations of state in tandem with those from molecular dynamics (MD) simulations based on density functional theory (DFT), whose applicability is limited to low temperatures (up to ∼ 106 K). Recent PIMC method developments employed a localized, Hartree-Fock nodal surface, allowing for a better description of bound states in warm dense silicon. In this work, we use the localized nodal scheme to study warm dense sodium at 2-fold ambient density. We demonstrate that PIMC and DFT-MD produce a coherent equation of state and discuss the electronic structure of the plasma.