论文部分内容阅读
Due to its low mass, hydrogen is expected to exhibit significant quantum effects, such as quantum delocalization, zero-point motion and quantum tunneling, especially under low temperatures and high pressures[l-3].In order to have deep insight into these quantum effects in dense hydrogen, we investigate the structure and dynamical properties of dense hydrogen at densities up to 100 g/cm3 with the temperature range of 0.1-1 eV using first-principle path-integral molecular dynamics (PIMD)[4-6] simulations based on density functional theory.The simulation results show that quantum nature of nuclei has a significant effect on the structure and thermodynamic properties.Most importantly, the quantum dynamics such as scattering determined ionic diffusion, electrical conductivity, and thermal conductivity could be largely different from the classical results using the improved path-integral centroid molecular dynamics[7].These results indicate that when the thermal de Broglie wavelength of nuclei is comparable with average interparticle distance, the nuclear quantum effects are not negligible even at high temperatures and give new results of structure and dynamical properties of dense matter under extreme conditions.For ice, by considering the nuclear NQEs, the phases around 100 Gpa are consistent with the previous experiments.The oxygen K edge with its shift is sensitive to the order-disorder transition, and therefore can be applied to diagnose the dynamics of ice structures [8].