Order-disorder
有序无序转变的计算机模拟——MC算法
一个样品做实验,从低温有序相,逐渐升温,到高温无序相。
模型假设:
1 模拟三维简单斜方,AB型合金,共有M*N*L个原子;
2 最邻近假设,即只考虑最邻近原子之间的相互作用,次邻近和更远的原子之间的作用忽略(误差较大),
,在简单斜方中,最邻近原子数z=6;
3 只考虑势能的作用,AA,BB,AB原子间的作用用Eaa,Ebb,Eab=Eba表示 且忽略振动能(原则上,温度很高时,不能忽略)等;
4 各原子之间的相互作用独立,即各化学键相互独立;
5 边界原子任然周期排列,只不过,邻近原子数减小,能量较高;边界面上的原子z=5;线
上的原子z=4,顶点上的原子z=3;由于顶点上只有四个原子,算法中不考虑这种情况;
6 其它假设。( Order-disorder transition of computer simulation- MC algorithm a sample experiment, from the low-temperature ordered phase, gradually warming up to a high temperature disordered phase. Model assumes that: 1 of three-dimensional rhombic, AB-type alloy, a total of M* N* L atoms 2 nearest the assumption that only consider the interaction between the neighboring atoms, and further sub-adjacent atoms ignore the interaction between the (larger error), , in the simple oblique Fang, nearest neighbor atoms, z = 6 3 only consider the potential role, AA, BB, AB interatomic with Eaa, Ebb, Eab = Eba representation and ignore the vibration energy (principle, the temperature is high, it can not be ignored), etc. 4 each atom interactions between independent, which means that each bond independently 5 boundary periodic arrangement of atoms in any course, but , adjacent atoms decreases, the higher energy boundary atomic plane z = 5 atoms on line z = 4, the vertex atoms z = 3 only four)
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