Incorporating Quantum Electrons in Classical Calculations for Dense Plasmas

Ab initio quantum molecular dynamics ‘QMD’ and density functional theory codes albeit the most accurate currently, often prove to be computationally intractable for studying shock dynamics. The present work aims to develop a computationally feasible approach to modelling shocks in low-Z dense plasma with partially degenerate electrons by identifying and implementing an effective potential for classical molecular dynamics ‘CMD’ simulations. The effective potential, fitted using the pair correlation function derived from QMD data, is used to simulate the shock Hugoniot with the code LAMMPS, which is then compared to the improved QMD equation-of-state table. Initial studies were conducted for deuterium plasmas using the AIREBO-M potential, given its success in modelling high-pressure hydrocarbons in ICF ablators, and the fitted potentials. This is done for both the weak and strong shock regime, including shock propagation and its release into a vacuum, with an allowed Hugoniot deviation of 20%. Following this, transport coefficients and shock structure are investigated to further test the accuracy of the effective potential.