- for(i=0;i<amount_si;i++) {
- /* calculation of new positions r(t+h) */
- si[i].x+=si[i].vx*tau;
- si[i].y+=si[i].vy*tau;
- si[i].z+=si[i].vz*tau;
- si[i].x+=(tau2*si[i].fx/m2);
- if(si[i].x>LX) si[i].x-=LEN_X;
- else if(si[i].x<-LX) si[i].x+=LEN_X;
- si[i].y+=(tau2*si[i].fy/m2);
- if(si[i].y>LY) si[i].y-=LEN_Y;
- else if(si[i].y<-LY) si[i].y+=LEN_Y;
- si[i].z+=(tau2*si[i].fz/m2);
- if(si[i].z>LZ) si[i].z-=LEN_Z;
- else if(si[i].z<-LZ) si[i].z+=LEN_Z;
- /* calculation of velocities v(t+h/2) */
- si[i].vx+=(tau*si[i].fx/m2);
- si[i].vy+=(tau*si[i].fy/m2);
- si[i].vz+=(tau*si[i].fz/m2);
- }
- for(i=0;i<amount_si;i++) {
- /* calculation of forces at new positions r(t+h) */
- for(j=0;j<i;j++) {
- deltax=si[i].x-si[j].x;
- if(deltax>LX) deltax-=LEN_X;
- else if(-deltax>LX) deltax+=LEN_X;
- deltax2=deltax*deltax;
- deltay=si[i].y-si[j].y;
- if(deltay>LY) deltay-=LEN_Y;
- else if(-deltay>LY) deltay+=LEN_Y;
- deltay2=deltay*deltay;
- deltaz=si[i].z-si[j].z;
- if(deltaz>LZ) deltaz-=LEN_Z;
- else if(-deltaz>LZ) deltaz+=LEN_Z;
- deltaz2=deltaz*deltaz;
- distance=deltax2+deltay2+deltaz2;
- if(distance<=R2_CUTOFF) {
- tmp=1.0/distance; // 1/r^2
- lj1=tmp; // 1/r^2
- tmp*=tmp; // 1/r^4
- lj1*=tmp; // 1/r^6
- tmp*=tmp; // 1/r^8
- lj2=tmp; // 1/r^8
- lj1*=tmp; // 1/r^14
- lj1*=LJ_SIGMA_12;
- lj2*=LJ_SIGMA_06;
- lj=-2*lj1+lj2;
- si[i].fx=lj*deltax;
- si[i].fy=lj*deltay;
- si[i].fz=lj*deltaz;
- si[i].fx=-lj*deltax;
- si[i].fy=-lj*deltay;
- si[i].fz=-lj*deltaz;
- }
- }
- /* calculation of new velocities v(t+h) */
- si[i].vx+=(tau*si[i].fx/m2);
- si[i].vy+=(tau*si[i].fy/m2);
- si[i].vz+=(tau*si[i].fz/m2);
- }
-
- if(!(runs%10)) {
-
- /* rasmol script & xyz file */
- sprintf(xyz,"./saves/si-%.15f.xyz",time);
- sprintf(ppm,"./video/si-%.15f.ppm",time);
- fd1=open(xyz,O_WRONLY|O_CREAT|O_TRUNC);
- if(fd1<0) {
- perror("rasmol xyz file open");
- return -1;
- }
- dprintf(fd2,"load xyz %s\n",xyz);
- dprintf(fd2,"spacefill 200\n");
- dprintf(fd2,"rotate x 11\n");
- dprintf(fd2,"rotate y 13\n");
- dprintf(fd2,"set ambient 20\n");
- dprintf(fd2,"set specular on\n");
- dprintf(fd2,"write ppm %s\n",ppm);
- dprintf(fd2,"zap\n");
- dprintf(fd1,"%d\nsilicon\n",amount_si);
- for(i=0;i<amount_si;i++)
- dprintf(fd1,"Si %f %f %f %f\n",
- si[i].x,si[i].y,si[i].z,time);
- close(fd1);
-
- }
-
- /* increase time */
- time+=tau;
- printf(".");
- fflush(stdout);
-
- }
-
- printf(" done\n");
- close(fd2);
- free(si);