High-pressure melting line of helium from <i>ab initio</i> calculations

Abstract

We applied two-phase simulations to directly calculate the high-pressure melting line of helium from 425 to 10 000 K and from 15 GPa to 35 TPa by using molecular dynamics based on density-functional theory. The implementation of the two-phase simulation method and the relaxation of the simulation to an equilibrium state was studied in detail, as well as its convergence with respect to particle number. We performed extensive two-phase simulations with the Perdew, Burke and Ernzerhof and the van der Waals density functional exchange-correlation functional and found almost identical results.