基于Kohn-Sham电子轨道依赖的交换关联泛函理论研究电子阻止本领中的电荷转移机制

项目名称： 基于Kohn-Sham电子轨道依赖的交换关联泛函理论研究电子阻止本领中的电荷转移机制

项目编号： No.11505092

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 毛飞

作者单位： 南华大学

项目金额： 21万元

中文摘要： 研究离子与物质的相互作用是核能，空间技术以及放射医学等应用领域的基础，对基础科学和应用科学都有重要意义。本项目旨在结合国际和国内关于材料电子阻止本领（Se）的最新研究进展，采用第一性原理分子动力学研究低能离子与电子碰撞时的电荷转移机制，开展纳米结构材料Se微观机制的研究。为了正确地描述离子碰撞过程中的电离和电荷转移效应，发展基于Kohn-Sham电子轨道依赖的交换关联泛函理论，该泛函能够正确地描述交换关联势对电子数的不连续性质和长程渐近行为。通过分析离子的电荷态和入射速度对电荷转移量的影响，研究低能离子与石墨烯分子和LiF纳米结构材料碰撞过程中的电荷转移效应。观察碰撞过程中体系Kohn-Sham电子能级的变化，探索电荷转移的物理机制，揭示其与弹靶的电子结构之间的依赖关系。研究低能质子和氦离子在3C-SiC和W中的Se，阐明电荷交换效应对Se的影响。建立一个包含了电荷转移效应的Se理论。

中文关键词： 辐照损伤效应；电子阻止本领；电荷转移；含时密度泛函理论；分子动力学

英文摘要： The study of the interaction between ions and matter is the basis of many applications in nuclear energy, space technology, radiotherapy and other areas, which is both important in fundamental and applied sciences. Following with the latest research progress on the electronic stopping power (Se) of materials, this project aims to investigate the mechanisms of charge transfer in the collisions between the low-energy ions and the electrons, and to study the micro-mechanism of the Se of nanostructured materials by employing ab initio molecular dynamics. In order to correctly describe the electronic ionization and charge transfer effects in the collision processes, the Kohn-Sham electron orbital dependent exchange-correlation functional theory will be developed, in which the derivative discontinuity and the long-range asymptotic behavior of the exchange-correlation potential are guaranteed. By analyzing the influences of different charge states and velocities of the ions on the number of transferred electrons, the charge transfer effect will be discussed when the low-energy ions are colliding with graphene molecule and LiF nanostructure. The physical mechanisms of charge transfer will be explored by monitoring the time evolution of Kohn-Sham eigenvalue spectra during the collision, and the dependence of the mechanisms on the electronic structures of the projectile and the target will be revealed. The Se of silicon carbide and tungsten when the low-energy protons and helium ions are traversing through them will be considered, and the influences of electron exchange on the Se will be clarified. The Se theory which includes the effects of charge transfer will be established.

英文关键词： Irradiation effects;Electronic stopping power;Electron transfer;Time-dependent density functional theory;Molecular dynamics