QUANTUM-MOLECULAR-DYNAMICS STIMULATIONS OF ISOTOPIC MIXTURES OF DENSE, HOT HYDROGEN

Calculations of isotopic binary mixtures of hydrogen over a range of densities and temperatures were performed using quantum-molecular-dynamics simulations. The electronic component was treated with three different models including density functional (local density approximation), tight binding, and effective pair potentials. Quantum-mechanical effects were found to be important even at elevated temperatures. Self-diffusion coefficients for each component became comparable in magnitude with increasing density in contradiction to simple mass-scaling rules. Mutual-diffusion coefficients tended to exceed the simple concentration average of the self-diffusion coefficients, but by less than 25%.