Advancing Finite-Temperature Orbital-Free Density Functional Theory with Pauli Potential

State-of-the-art approach of investigating high-energy-density matter over a large range of densities and temperatures heavily relies on Mermin-Kohn-Sham (MKS) density functional theory (DFT). Unfavorable scaling of MKS implementations with respect to the temperature and system size limits both the speed of computation and its applicability to the phenomena requiring large simulation cells. Alternatively, finite-temperature orbital-free (OF) DFT offers attractive scaling yet suffering from missing of discrete atomic shell structures due to the Pauli potential being unknown as a functional of electronic density. To alleviate the inaccuracy of OF-DFT, we first demonstrate that the exact forms of Pauli potential in terms of MKS orbitals are identical with and without entropic contribution. We further consider the possibility of implementing the Pauli potential into the self-consistent field (SCF) calculation of OF-DFT. The procedure of extracting the single-atom contribution to the Pauli potential of extended system and effectively making it part of the pseudopotential for later use in OF calculation is discussed. In this manner, the Pauli potential becomes frozen and is no longer updated during the OF SCF step – the consequences of this approximation is overviewed. Examples to demonstrate this approach for warm-dense matter simulations will be given.