可变元胞分子动力学方法对晶体结构稳定性的研究

CRYSTAL STRUCTURE STABILITY STUDY BY MOLECULAR DYNAMICS METHOD WITH VARIABLE CELL

本文利用可变元胞的分子动力学方法(MD),研究了离子束辐照条件下的晶体结构稳定性问题,计算证实了铜、银、铝等金属在常压下,面心结构是稳定的。 在三维分子动力学程序中,使用了跳点法差分格式,并对原格式作了修正。计算表明,这样的差分格式较常用的 Euler-Cauchy 法和四阶 Runge-Kutta 法节省机时,且占用较小的贮存单元。

In this paper, the cryatal structure stability of metals irradiated by ion beam is investigated by molecular dynamics method with variable cell. The phase transformation process of copper, aluminium and silver metals under pressure are simulated. It is confirmed that tor Cu. Ag, Al at normal conditions fee structure is stable.In our three dimensional MD program, the leapfrog method is used and some of this difference scheme are duly revised. Through calculation, it is clear that present difference scheme spends less CPU time and occupies less storage units than both Euler-Cauchy and Runge-Kutta methods.