Influence of ordered structures on electrical conductivity and XANES from warm to hot dense matter

The detailed ionic structure of matter from the warm to the hot dense matter regime and its influence on the electrical conductivity and X-ray absorption near-edge spectroscopy (XANES) is studied using the method of quantum Langevin molecular dynamics (QLMD). It is found that the local ordered structures play a pivotal role in the conductivity and XANES when the ionic structure of the matter is transformed from long-range to medium-short-range order and finally to disorder as the temperature increases. Local short-range ordered structures such as chains and circles appear at high temperatures. For a given macroscopic density-temperature point, the dynamical changes of the atomic configurations in the QLMD simulation give rise to variations in the calculated physical properties, indicating that some dynamical features might be lost in usual static models such as average atom and hypernetted-chain (HNC) models.