Momentum distribution functions and pair correlation functions of unpolarized uniform electron gas in warm dense matter regime

Abstract: In this paper we continued our research of the uniform electron gas, using the single--momentum path integral Monte Carlo method, and studied the momentum distribution functions and the pair correlation functions in the warm dense matter regime. We discovered that the single--particle momentum distribution function deviates from the Fermi distribution and forms so-called "quantum tails" at high momenta, if non-ideality is strong enough in both degenerate and non-degenerate cases. This effect is always followed by the appearance of the short--range order on the pair distribution functions and can be explained via the tunneling through the effective potential wells surrounding the electrons. Also we calculated the average kinetic and potential energies in the wide range of states, expanding our previous results significantly.