The dynamic electron–ion collisions play an important role in determining the static and transport properties of warm dense matter (WDM). The electron force field (EFF) method is applied to study the ionic transport properties of warm dense hydrogen. Compared with the results from quantum molecular dynamics and orbital-free molecular dynamics, the ionic diffusions are largely reduced by involving the dynamic collisions of electrons and ions. This physics is verified by the quantum Langevin molecular dynamics (QLMD) simulations, which includes electron–ion collision-induced friction (EI-CIF) into the dynamic equation of ions. Based on these new results, we proposed a model including the correction of collision-induced friction of the ionic diffusion. The CIF model has been verified to be valid in a wide range of densities and temperatures. We also compare the results with the Yukawa one-component plasma (YOCP) model and Effective OCP (EOCP) model. We proposed to calculate the self-diffusion coefficients using the EOCP model modified by the CIF model to introduce the dynamic electron–ion collision effect.

Lattice thermal conductivity ($\kappa_{\rm{lat}}$) of $\rm{MgSiO_3}$ perovskite and post-perovskite is an important parameter for the thermal dynamics in the Earth. Here, we developed a deep potential of density functional theory quality over the entire thermodynamic conditions in the lower mantle, and calculate the $\kappa_{\rm{lat}}$ by the Green-Kubo relation. Deep potential molecular dynamics captures full-order anharmonicity and considers ill-defined phonons in low-$\kappa_{\rm{lat}}$ materials ignored in the phonon gas model. The $\kappa_{\rm{lat}}$ shows negative temperature dependencce and positive linear pressure dependence. Interestingly, the $\kappa_{\rm{lat}}$ undergos an increase at the phase boundary from perovskite to post-perovskite. We demonstrate that, along the geotherm, the $\kappa_{\rm{lat}}$ increases by 18.2% at the phase boundary. Our results would be helpful for evaluating Earth's thermal dynamics and improving the Earth model.

Accurate knowledge of the equation of state (EOS) of deuterium–tritium (DT) mixtures is critically important for inertial confinement fusion (ICF). Although the study of EOS is an old topic, there is a longstanding lack of global accurate EOS data for DT within a unified theoretical framework. DT fuel goes through very wide ranges of density and temperature from a cold condensed state to a hot dense plasma where ions are in a moderately or even strongly coupled state and electrons are in a partially or strongly degenerate state. The biggest challenge faced when using first-principles methods for obtaining accurate EOS data for DT fuel is the treatment of electron–ion interactions and the extremely high computational cost at high temperatures. In the present work, we perform extensive state-of-the-art ab initio quantum Langevin molecular dynamics simulations to obtain EOS data for DT mixtures at densities from 0.1 g/cm3 to 2000 g/cm3 and temperatures from 500 K to 2000 eV, which are relevant to ICF processes. Comparisons with average-atom molecular dynamics and orbital-free molecular dynamics simulations show that the ionic strong-coupling effect is important for determining the whole-range EOS. This work can supply accurate EOS data for DT mixtures within a unified ab initio framework, as well as providing a benchmark for various semiclassical methods.

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