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)