摘要
采用Stillinger-Weber相互作用势能对原子体系的内聚能进行计算,但根据目前已知的参数,通过GULP软件模拟得到的部分金刚石结构材料的某些性质与实验值相差较大。针对上述情况,以金刚石结构Si为研究对象,运用GULP软件对Si的SW势函数参数进行修正,并计算了优化后Si的内聚能、晶格常数、体积模量和弹性常数等参数,结果与实验值很符合;以此为基础,采用分子动力学方法,模拟了金刚石结构Si晶体中空位运动过程的能量变化,并对空位运动的方向和势垒进行了分析和讨论。
The Stillinger-Weber （SW） potential can be used in the atomistic calculations of the cohesive energy. However, according to the given SW potential parameters, some properties of diamond-cubic materials calculated by the code GULP are far from the experimental values. Based upon the fact above, Si （diamond-cubic） is taken as the main subject of this research, and the SW potential parameters of Si are modified by GULP. The cohesive energy, lattice constant and bulk modulus of Si are also calculated by using the modified SW potential parameters. The new result comes to be highly consistent with the experimental values. Thus the modified potential is used to simulate the energy change of vacancy movement by molecular dynamics, and the direction and energy barriers of vacancy movement are also analyzed and discussed.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2008年第8期123-126,共4页
Materials Reports
关键词
分子动力学
相互作用势
空位
molecular dynamics, interatomic potential, vacancy
