24小时热门版块排行榜

返回列表

mathsphy

新虫 (小有名气)

应助: 1 (幼儿园)
金币: 419
帖子: 94
在线: 8.9小时
虫号: 3485761
注册: 2014-10-20
专业: 金属材料的微观结构

[求助] 为什么两个碰撞后能量发散了? 已有2人参与

大家好,我初学lammps,今天做两个铁原子碰撞时程序提示有原子丢失,所以我就使用了可变时间步长,结果发现它系统的能量不太对,所以想请教一下.
我这个系统就只建了一个5*5*5的晶胞,然后放了三个原子,坐标分别是(0,0,0),(0,3,3),(0,3,0),晶格单位.
第一个原子是用作参考的,第二个原子碰撞第三个原子.系综和设置如下:
fix 1 all nve
fix 2 all dt/reset 1 NULL 0.001 0.01
velocity 1 set 1000 0 0
velocity 2 set 0 0 -1000
velocity 3 set 0 0 0

输出的信息如下,其中最右边三列分别代表第1,2,3原子的动能:
Step Dt Time Temp TotEng PotEng KinEng 4 5 6
   0    1e-005          0 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   10    1e-005    0.0001 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   20    1e-005    0.0002 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   30    1e-005    0.0003 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   40    1e-005    0.0004 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   50    1e-005    0.0005 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   60    1e-005    0.0006 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   70    1e-005    0.0007 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   80    1e-005    0.0008 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   90    1e-005    0.0009 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   100    1e-005       0.001 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   110    1e-005    0.0011 1.8351477e+008 47442.293          0 47442.293 23721.146 23721.146          0
   120    1e-005    0.0012 1.8351477e+008 47442.293 -2.2147594e-005 47442.293 23721.146 23721.146 5.3606842e-015
   130 9.9999999e-006    0.0013 1.8351478e+008 47442.293 -0.00057027847 47442.293 23721.146 23721.147 3.4424435e-012
   140 9.9999994e-006    0.0014 1.8351478e+008 47442.293 -0.002693678 47442.295 23721.146 23721.149 7.6714312e-011
   150 9.9999977e-006    0.0015 1.8351481e+008 47442.293 -0.010243151 47442.303 23721.146 23721.157 1.108068e-009
   160 9.9999835e-006 0.0015999999 1.8351504e+008 47442.293 -0.067726385 47442.361 23721.146 23721.215 4.9021806e-008
   170 9.9998924e-006 0.0016999994 1.8351669e+008 47442.293  -0.49445878 47442.787 23721.146 23721.641 2.5772336e-006
   180 9.9997992e-006 0.0017999979 1.8351836e+008 47442.293  -0.92702466    47443.22 23721.146 23722.074 9.0716298e-006
   190 9.9996775e-006 0.0018999954 1.8352057e+008 47442.293 -1.497937 47443.791 23721.146 23722.645 2.3667644e-005
   200 9.9995503e-006 0.0019999916 1.8352292e+008 47442.293 -2.1048515 47444.398 23721.146 23723.252 4.6713654e-005
   210 9.9994425e-006 0.0020999866 1.8352492e+008 47442.293 -2.6212737 47444.914 23721.146 23723.768 7.2437174e-005
   220 9.9993716e-006 0.0021999806 1.8352627e+008 47442.293 -2.9705227 47445.263 23721.146 23724.117 9.3009162e-005
   230 9.9993898e-006 0.0022999743 1.8352597e+008 47442.293 -2.8944083 47445.188 23721.146 23724.041 8.8322947e-005
   240 9.9997456e-006 0.0023999692 1.8351944e+008 47442.287 -1.2123728    47443.5 23721.146 23722.353 1.5352359e-005
   250    1e-005 0.0024999687 1.8347824e+008 47442.269 9.4212164 47432.847 23721.146    23711.7 0.00094058064
   260    1e-005 0.0025999687 1.8330903e+008    47442.22 53.116248 47389.104 23721.146 23667.928  0.029882795
   270    1e-005 0.0026999687 1.8275428e+008 47442.011 196.32033 47245.691 23721.146 23524.134 0.41077332
   280    1e-005 0.0027999687 1.8045156e+008    47440.57 790.17944    46650.39 23721.146 22922.405 6.8394779
   290 8.1905831e-012 0.0028299688 2.7355272e+020 7.0718929e+016 165.60334 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016
   300 8.1905831e-012 0.0028299689 2.7355272e+020 7.0718929e+016 6.8461037 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016
   310 8.1905831e-012 0.0028299689 2.7355272e+020 7.0718929e+016 -2.9300923 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016
   320 8.1905831e-012  0.002829969 2.7355272e+020 7.0718929e+016 -2.556017 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016
   330 8.1905831e-012 0.0028299691 2.7355272e+020 7.0718929e+016 -1.4125551 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016
   340 8.1905831e-012 0.0028299692 2.7355272e+020 7.0718929e+016  -0.44704995 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016
   350 8.1905831e-012 0.0028299693 2.7355272e+020 7.0718929e+016 -0.0086311757 7.0718929e+016 23721.146 3.5359435e+016 3.5359493e+016

我不明白为啥会发散啊.....请问要怎么解决这个问题?...