Extended first-principles molecular dynamics model for high temperature simulations in the ABINIT code: Application to warm dense aluminum

The extended first-principles molecular dynamics (Extended FPMD) model introduced by Zhang et al. [2], based on an analytical single plane wave description of electronic orbitals for high energy electrons, has been implemented within the ab initio DFT software package ABINIT and is now available. This model allows quantum simulations to be done smoothly on the full range of temperatures from cold condensed matter to hot dense plasmas passing through the warm dense matter regime which was currently not possible within the same ab initio model due to numerical limitations. In addition to presenting a brief theoretical background of the Zhang et al. method, we propose some improvements to the model. We then present the details of the implementation, and finally offer an application to the aluminum simulations for multiple densities, from room temperature to hot (thousands of eVs) temperature ranges, with a resulting Hugoniot equation of state that we compare with other methods. (C) 2021 Elsevier B.V. All rights reserved.