We present melting curves of aluminum, copper, and nickel calculated on the basis of a quasiharmonic approximation. The dependence of a phonon density of states on electron temperature is taken into account for both thermodynamic properties and a mean square displacement of atoms. Linear expansion coefficients are strongly dependent on an approximation of the exchange-correlation functional; the generalized gradient approximation gives better results at normal conditions. Using the Lindemann criterion we obtain good agreement with experimental pressure dependences of the melting temperature for Al and Cu. In the case of Ni we consider a spin polarization effect to reproduce a recent first-principle simulation and shock-wave data. However, our melting curve is located significantly higher than static experimental points. We also consider a thermal excitation of electrons in a crystal and investigate the dependence of the melting temperature on the electronic one at normal and elevated densities. Hardening of the crystal structure for all the metals is obtained in our simulation; this effect might be confirmed experimentally owing to a relatively long lifetime of the two-temperature state.

We present quantum molecular dynamics calculations of principal, porous, and double shock Hugoniots, release isentropes, and sound velocity behind the shock front for aluminum. A comprehensive analysis of available shock-wave data is performed; the agreement and discrepancies of simulation results with measurements are discussed. Special attention is paid to the melting region of aluminum along the principal Hugoniot; the boundaries of the melting zone are estimated using the self-diffusion coefficient. Also, we make a comparison with a high-quality multiphase equation of state for aluminum. Independent semiempirical and first-principle models are very close to each other in caloric variables (pressure, density, particle velocity, etc.) but the equation of state gives higher temperature on the principal Hugoniot and release isentropes than ab initio calculations. Thus, the quantum molecular dynamics method can be used for calibration of semiempirical equations of state in case of lack of experimental data.

We present quantum molecular dynamics calculations of thermodynamic properties of expanded liquid tungsten. Experiments on shock compression of porous tungsten and its subsequent expansion into different anvil materials are successfully reproduced. Special attention is paid to available isobaric expansion experimental data and theoretical estimations of the critical point. Density on our first-principles 1 kbar isobar of liquid tungsten is slightly higher than in most wire-explosion experiments and the slope of the isobar is more flat. The dependence of the specific enthalpy on temperature is in good agreement with dynamic heating experimental data. A special Monte Carlo analysis has been applied for the estimation of the liquid-gas coexistence curve and critical point parameters of tungsten. The result is close to an estimation obtained with Likalter's similarity relation.

In the present work, we compare the thermal contribution of electrons to thermodynamic functions of metals in different models at high densities and electron temperatures. One of the theoretical approaches, the full-potential linear-muffin-tin-orbital method, treats all electrons in the framework of density functional theory (DFT). The other approach, VASP, uses projector-augmented-wave pseudopotentials for the core electrons and considers the valent electrons also in the context of DFT. We analyze the limitations of the pseudopotential approach and compare the DFT results with a finite-temperature Thomas-Fermi model and two semiempirical equations of state.

We present quantum molecular dynamics calculations of thermophysical properties of solid and liquid molybdenum in the vicinity of melting. Detailed analysis of available experimental isobaric expansion data and extensive comparison over a wide set of properties with results of first-principle calculations is presented, possible reasons of contradictions are discussed. Accurate calculation of zero isobar confirms the density of solid Mo measured by electrostatic levitation technique and the lowest density of molten Mo observed in pulse heating experiments, that gives a substantial volume change on melting of about 5.5%.