/*
* posic.c - precipitation process of silicon carbide in silicon
*
- * author: Frank Zirkelbach <hackbard@hackdaworld.org>
+ * author: Frank Zirkelbach <frank.zirkelbach@physik.uni-augsburg.de>
*
*/
+
+#include <math.h>
#include "moldyn.h"
#include "math/math.h"
int main(int argc,char **argv) {
t_moldyn md;
-
t_atom *si;
-
t_visual vis;
-
t_random random;
int a,b,c;
- double t,e,u;
+ double e,u;
double help;
t_3dvec p;
int count;
t_lj_params lj;
+ t_ho_params ho;
- char fb[32]="saves/fcc_test";
+ /* parse arguments */
+ a=moldyn_parse_argv(&md,argc,argv);
+ if(a<0) return -1;
/* init */
-
+ moldyn_log_init(&md,&vis);
rand_init(&random,NULL,1);
random.status|=RAND_STAT_VERBOSE;
// printf("%f %f\n",rand_get_gauss(&random),
// rand_get_gauss(&random));
- visual_init(&vis,fb);
-
a=LEN_X;
b=LEN_Y;
c=LEN_Z;
- t=TEMPERATURE;
+ /* set for 'bounding atoms' */
+ vis.dim.x=a*LC_SI;
+ vis.dim.y=b*LC_SI;
+ vis.dim.z=c*LC_SI;
+ /* init lattice
printf("placing silicon atoms ... ");
- //count=create_lattice(DIAMOND,Si,M_SI,LC_SI,a,b,c,&si);
- //printf("(%d) ok!\n",count);
+ count=create_lattice(DIAMOND,SI,M_SI,LC_SI,a,b,c,&si);
+ printf("(%d) ok!\n",count); */
+ /* testing purpose */
count=2;
si=malloc(2*sizeof(t_atom));
- si[0].r.x=2.0;
+ si[0].r.x=0.35*sqrt(3.0)*LC_SI/2.0;
si[0].r.y=0;
si[0].r.z=0;
- si[0].element=Si;
- si[0].mass=14.0;
- si[1].r.x=-2.0;
+ si[0].element=SI;
+ si[0].mass=M_SI;
+ si[1].r.x=-si[0].r.x;
si[1].r.y=0;
si[1].r.z=0;
- si[1].element=Si;
- si[1].mass=14.0;
-
- printf("setting thermal fluctuations\n");
- //thermal_init(si,&random,count,t);
- v3_zero(&(si[0].v));
- v3_zero(&(si[1].v));
+ si[1].element=SI;
+ si[1].mass=M_SI;
+ /* */
- /* check kinetic energy */
-
- e=get_e_kin(si,count);
- printf("kinetic energy: %f\n",e);
- printf("3/2 N k T = %f\n",1.5*count*K_BOLTZMANN*t);
-
- /* check total momentum */
- p=get_total_p(si,count);
- printf("total momentum: %f\n",v3_norm(&p));
-
- /* check potential energy */
+ /* moldyn init (now si is a valid address) */
md.count=count;
md.atom=si;
md.potential=potential_lennard_jones;
md.force=force_lennard_jones;
- //md.cutoff_square=((LC_SI/4.0)*(LC_SI/4.0));
- md.cutoff_square=36.0;
+ //md.potential=potential_harmonic_oscillator;
+ //md.force=force_harmonic_oscillator;
+ md.cutoff=R_CUTOFF;
+ md.cutoff_square=(R_CUTOFF*R_CUTOFF);
md.pot_params=&lj;
+ //md.pot_params=&ho;
md.integrate=velocity_verlet;
- md.time_steps=RUNS;
- md.tau=TAU;
+ //md.time_steps=RUNS;
+ //md.tau=TAU;
md.status=0;
md.visual=&vis;
- lj.sigma6=3.0/16.0*LC_SI*LC_SI;
+ printf("setting thermal fluctuations (T=%f K)\n",md.t);
+ //thermal_init(&md,&random,count);
+ for(a=0;a<count;a++) v3_zero(&(si[0].v));
+ //v3_zero(&(si[0].v));
+ //v3_zero(&(si[1].v));
+
+ /* check kinetic energy */
+
+ e=get_e_kin(si,count);
+ printf("kinetic energy: %.40f [J]\n",e);
+ printf("3/2 N k T = %.40f [J]\n",1.5*count*K_BOLTZMANN*md.t);
+
+ /* check total momentum */
+ p=get_total_p(si,count);
+ printf("total momentum: %.30f [Ns]\n",v3_norm(&p));
+
+ /* check potential energy */
+ lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI;
help=lj.sigma6*lj.sigma6;
lj.sigma6*=help;
lj.sigma12=lj.sigma6*lj.sigma6;
- lj.epsilon=10000;
+ lj.epsilon=LJ_EPSILON_SI;
+
+ ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
+ ho.spring_constant=LJ_EPSILON_SI;
u=get_e_pot(&md);
- printf("potential energy: %f\n",u);
- printf("total energy (1): %f\n",e+u);
- printf("total energy (2): %f\n",get_total_energy(&md));
+ printf("potential energy: %.40f [J]\n",u);
+ printf("total energy (1): %.40f [J]\n",e+u);
+ printf("total energy (2): %.40f [J]\n",get_total_energy(&md));
md.dim.x=a*LC_SI;
md.dim.y=b*LC_SI;
md.dim.z=c*LC_SI;
+ printf("estimated accurate time step: %.30f [s]\n",
+ estimate_time_step(&md,3.0,md.t));
+
+
/*
* let's do the actual md algorithm now
*
* integration of newtons equations
*/
- /* visualize */
- //visual_atoms(&vis,0.0,si,count);
-
-
moldyn_integrate(&md);
- printf("total energy (after integration): %f\n",get_total_energy(&md));
+ printf("total energy (after integration): %.40f [J]\n",
+ get_total_energy(&md));
/* close */
- visual_tini(&vis);
-
rand_close(&random);
-
-
- //printf("starting velocity verlet: ");
- //fflush(stdout);
-
- //for(runs=0;runs<RUNS;runs++) {
-
- /*
- * velocity verlet
- *
- * r(t+h) = r(t) + h * dr/dt|t + h^2/2m * F(t)
- * dr/dt|(t+h) = dr/dt|t + h/2m * (F(t) + F(t+h))
- *
- */
- //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);
-// /* reset of forces */
-// si[i].fx=.0;
-// si[i].fy=.0;
-// si[i].fz=.0;
-// }
-// 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[j].fx+=lj*deltax;
-// si[j].fy+=lj*deltay;
-// si[j].fz+=lj*deltaz;
-// }
-// }
-// }
-// for(i=0;i<amount_si;i++) {
-// /* 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%150)) {
-//
-// /* 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,"zoom 400\n");
-// dprintf(fd2,"write ppm %s\n",ppm);
-// dprintf(fd2,"zap\n");
-// dprintf(fd1,"%d\nsilicon\n",amount_si+9);
-// 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);
-// dprintf(fd1,"H 0.0 0.0 0.0 %f\n",time);
-// dprintf(fd1,"He %f %f %f %f\n",LX,LY,LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",-LX,LY,LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",LX,-LY,LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",LX,LY,-LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",-LX,-LY,LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",-LX,LY,-LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",LX,-LY,-LZ,time);
-// dprintf(fd1,"He %f %f %f %f\n",-LX,-LY,-LZ,time);
-// close(fd1);
-//
-// }
-//
-// /* increase time */
-// time+=tau;
-// printf(".");
-// fflush(stdout);
-//
-// }
-//
-// printf(" done\n");
-// close(fd2);
-// free(si);
-//
+ moldyn_shutdown(&md);
+
return 0;
}
projects / physik / posic.git / blobdiff