Study On The Interactions And Structures Of Warm Dense Matter

Warm dense matter(WDM),whose density is above the solid density and temperature is around the Fermi temperature,exists widely in planet interior,the processes of strong laser interaction with matter,and shock compression experiments et al.Its mechanical and optical properties differ from ordinary solids,ideal plasmas.And its structure,equation of states,transport properties et al.play important roles in the simulations and analyses of the molecular dynamics and hydrodynamics models.The ionic structures,electronic structures,equation of states,and transport properties of the warm dense matter at temperatures from 0.1 to 100 e V and densities betweem 1 and 5 times solid density,are studied by the molecular dynamics.The density functional theory,orbital free approximation,semiepirical methods et al.are used to describe the interactions among the ions and electrons.The roles of the interactions on the physical properties are analysed,and the applicability of the models are discussed.In this work,three typical warm dense matters are selected,and first principles molecular dynamics are carried out on a wide density and temperature regime.The equation of states,and transport properties are studied.The local structures and interactions among the atoms,and their influence on the transport properties are discussed.[1] The multi-component silane(Si H4)at high pressure and temperature has very fruitful structures and phases.The silane from 1.795 g/cm~3,300 K to 3.844 g/cm~3,3 e V are calculated by the quantum molecular dynamics method.The local ion clusters are analysed and their characteristics with the density and temperature are revealed.The melting,dissociation,electron structure,nonmetal-to-metal transition are discussed too.[2] Warm and hot dense iron is a typical system with many electrons and strong coupling.The structures and transport properties of iron from 0.8 g/cm~3,80 e V to 40g/cm~3,240 e V are calculated.The electron screening,exchange,ion environment effects are discussed,and the corrections of the Yukawa model are added.[3] Shock compressed argon from van der Waals interaction dominated regime to warm dense regime are concerned.The argon from 0.5 g/cm~3,300 K to 5.5 g/cm~3,3 e V are calculated by the molecular dynamics method.The van der Waals interactions, electronic excitation,many body interaction are discussed,and the density functional theory with van der Waals interaction,fitted pair potentials,pair and three potentials from quantum chemical calculations are assessed.The electron structures and insulator-to-conductor transition are analysed too.The neural network potential-energy surfaces are realized,and the cases of dense H are used to check the models.From the discussion of the structures and dynamics of the matter with different interactions,we provided an overall view of the structures,transport properties,and interactions in the dense matter.And we realize the extending of the first-principles calculation using neural network.