温稠密物质的相互作用与结构研究

发布时间：2017-12-27 21:13

本文关键词：温稠密物质的相互作用与结构研究　出处：《国防科学技术大学》2016年博士论文　论文类型：学位论文

【摘要】：在行星内部、强激光物质相互作用、冲击压缩实验中,物质的密度会处于固体密度附近或以上、温度则在费米温度附近,即位于温稠密区域。这种温稠密物质的力学、光学性质区别于典型的固体、理想等离子体,它的结构、物态方程、输运性质等在相关的分子动力学、流体力学等模拟和分析中扮演非常关键的角色。本文利用分子动力学方法,基于密度泛函、无轨道近似、半经验势等方法描述温稠密物质电子、离子间相互作用,研究了温度从0.1eV到200eV,密度从固态密度到5倍固体密度的离子和电子结构、状态方程和输运性质,并讨论了各种相互作用势的适用性和对物理性质的影响。[1]温稠密的硅烷(SiH_4)是多组分的复杂体系,有非常丰富的相图和结构。利用量子分子动力学方法研究了1.795～3.844g/cm~3、300K～3eV的硅烷,分析了温稠密物质区别于高温等离子体的局域结构特点,并揭示了这些特征随温度密度的变化。也对其中熔化、解离、电子结构、绝缘体-金属转变进行了研究。[2]温、热稠密的铁是典型的多电子、强耦合体系。通过密度从0.1倍到5倍固体密度的铁在80eV到240eV的结构特性和输运性质的分析,我们讨论了电子屏蔽、交换、离子环境效应,并修正了Yukawa等解析模型。[3]对冲击压缩氩的计算则横跨范德瓦尔斯主导体系和温稠密物质区域。通过0.5～5.5g/cm~3、300K～3eV区间上的Ar的分子动力学计算,讨论了其中范德瓦尔斯作用、电子激发、多体相互作用的特点,在此基础上,评估了密度泛函以及它的范德瓦尔斯修正、拟合对势、量子化学对势、三体势的特点,也分析了电子结构以及绝缘体-导体转变。实现了利用神经网络构建第一原理精度的稠密物质相互作用势能面,利用稠密H对模型做了基本检验。讨论不同相互作用下物质结构及其动力学,我们分析了温稠密物质的结构特性、输运性质以及稠密物质的相互作用特点,同时我们也初步实现了神经网络对第一原理计算的扩展。
[Abstract]:In the planetary interior, strong laser material interaction and impact compression experiments, the density of matter will be near or above the solid density, and the temperature will be near the Fermi temperature, that is, it is located in the dense region. The mechanical and optical properties of this dense material are different from the typical solid and ideal plasmas. Their structure, equation of state and transport properties play a key role in molecular dynamics, fluid dynamics and other simulation and analysis. In this paper, using the method of molecular dynamics, density functional, orbital approximation and semi empirical potential method to describe the interaction between electrons and ions of warm dense matter based on the study of temperature from 0.1eV to 200eV, the density of ions and electrons from the solid density to the structure, state equation and transport properties of 5 times the solid density, are discussed. Influence of the applicability of various interaction potential and the physical properties of the. The dense silane (SiH_4) of [1] is a complex system of multiple components, with very rich phase diagrams and structures. The quantum molecular dynamics method was used to study the 1.795 ~ 3.844g/cm~3, 300K ~ 3eV silane. The local structure characteristics of the dense materials were analyzed, and the change of these characteristics with temperature density was revealed. The melting, dissociation, electronic structure, and insulator - metal transition are also studied. [2] warm and dense iron is a typical multi electron and strong coupling system. By analyzing the structure and transport properties of iron from 0.1 times to 5 times solid density in 80eV to 240eV, we have discussed the electron shielding, exchange and ion environmental effects, and revised the analytical models such as Yukawa. The calculation of the impact compression argon by [3] crosses the Van Der Waals dominant system and the warm dense material region. By 0.5 ~ 5.5g/cm~3, 300K ~ 3eV interval on Ar molecular dynamics calculation, discusses the role of Van Der Waals, electronic excitation, multi-body interaction characteristics, based on the density functional evaluation and its correction, Van Der Waals fitting characteristics of the potential, quantum chemical potential, the potential of three, are also analyzed change of electronic structure and insulator conductor. A dense material interaction potential energy surface is realized by using the neural network to construct the first principle precision, and the basic test of the model is done by using dense H. The structure and dynamics of matter under different interactions are discussed. We have analyzed the structure and transport properties of dense materials, and the interaction characteristics of dense matter. At the same time, we have preliminarily realized the extension of neural network to the first principles calculation.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O469

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