init/init.c

   1 /*
   2  * init.c - create initial conditions
   3  *
   4  * author: Frank Zirkelbach <frank.zirkelbach@physik.uni-augsburg.de>
   5  *
   6  */
   7
   8 #include "../math/math.h"
   9 #include "../moldyn.h"
  10
  11 /* fcc lattice init */
  12 int fcc_init(t_3dvec *dim,double lc,t_atom *atom,t_3dvec *origin) {
  13
  14         int count;
  15         int i,j;
  16         t_3dvec o,r,n;
  17         t_3dvec basis[3];
  18         double help[3];
  19
  20         if(origin) v3_copy(&o,origin);
  21         else v3_zero(&o);
  22
  23         /* construct the basis */
  24         for(i=0;i<3;i++) {
  25                 for(j=0;j<3;j++) {
  26                         if(i!=j) help[j]=0.5*lc;
  27                         else help[j]=.0;
  28                 }
  29                 v3_set(&basis[i],help);
  30         }
  31
  32         v3_zero(&r);
  33         v3_add(&r,&r,&o);
  34         count=0;
  35
  36         /* fill up the room */
  37         while(r.x<dim->x) {
  38                 while(r.y<dim->y) {
  39                         while(r.z<dim->z) {
  40                                 v3_copy(&(atom[count].r),&r);
  41                                 count+=1;
  42                                 for(i=0;i<3;i++) {
  43                                         v3_add(&n,&r,&basis[i]);
  44                                         if((n.x<dim->x+o.x)&&(n.y<dim->y+o.y)&&(n.z<dim->z+o.z)) {
  45                                                 v3_copy(&(atom[count].r),&n);
  46                                                 count+=1;
  47                                         }
  48                                 }
  49                                 r.z+=lc;
  50                         }
  51                         r.y+=lc;
  52                 }
  53                 r.x+=lc;
  54         }
  55
  56         /* coordinate transformation */
  57         help[0]=dim->x/2.0;
  58         help[1]=dim->y/2.0;
  59         help[2]=dim->z/2.0;
  60         v3_set(&n,help);
  61         for(i=0;i<count;i++)
  62                 v3_sub(&(atom[i].r),&(atom[i].r),&n);
  63
  64         return count;
  65 }
  66
  67 int diamond_init(t_3dvec *dim,double lc,t_atom *atom,t_3dvec *origin) {
  68
  69         int count;
  70         t_3dvec o;
  71
  72         count=fcc_init(dim,lc,atom,origin);
  73
  74         o.x=0.25*lc;
  75         o.y=0.25*lc;
  76         o.z=0.25*lc;
  77
  78         if(origin) v3_add(&o,&o,origin);
  79
  80         count+=fcc_init(dim,lc,&atom[count],&o);
  81
  82
  83         return count;
  84 }