/*
* 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_atom *si;
- int a,b,c;
+ t_moldyn md;
- char fb[32]="saves/fcc_test";
+ t_atom *si;
t_visual vis;
+ t_random random;
+
+ int a,b,c;
+ double t,e,u;
+ double help;
+ t_3dvec p;
int count;
+ t_lj_params lj;
+ t_ho_params ho;
+
+ char fb[32]="saves/lj_test";
+
+ /* init */
+
+ rand_init(&random,NULL,1);
+ random.status|=RAND_STAT_VERBOSE;
+
+ /* testing random numbers */
+ //for(a=0;a<1000000;a++)
+ // 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;
-
- visual_init(&vis,fb);
- /* init */
- printf("placing silicon atoms\n");
- count=create_lattice(FCC,Si,M_SI,LC_SI,a,b,c,&si);
+ vis.dim.x=a*LC_SI;
+ vis.dim.y=b*LC_SI;
+ vis.dim.z=c*LC_SI;
+
+ t=TEMPERATURE;
+
+ printf("placing silicon atoms ... ");
+ //count=create_lattice(DIAMOND,Si,M_SI,LC_SI,a,b,c,&si);
+ //printf("(%d) ok!\n",count);
+ count=2;
+ si=malloc(2*sizeof(t_atom));
+ si[0].r.x=0.16e-9;
+ si[0].r.y=0;
+ si[0].r.z=0;
+ si[0].element=SI;
+ si[0].mass=M_SI;
+ si[1].r.x=-0.16e-9;
+ si[1].r.y=0;
+ si[1].r.z=0;
+ si[1].element=SI;
+ si[1].mass=M_SI;
- visual_atoms(&vis,0.0,si,count);
+ printf("setting thermal fluctuations\n");
+ //thermal_init(si,&random,count,t);
+ 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*t);
+
+ /* check total momentum */
+ p=get_total_p(si,count);
+ printf("total momentum: %.30f [Ns]\n",v3_norm(&p));
+
+ /* check potential energy */
+ md.count=count;
+ md.atom=si;
+ md.potential=potential_lennard_jones;
+ //md.potential=potential_harmonic_oscillator;
+ md.force=force_lennard_jones;
+ //md.force=force_harmonic_oscillator;
+ //md.cutoff_square=((LC_SI/4.0)*(LC_SI/4.0));
+ md.cutoff=(0.4e-9);
+ md.cutoff_square=(0.6e-9*0.6e-9);
+ md.pot_params=&lj;
+ //md.pot_params=&ho;
+ md.integrate=velocity_verlet;
+ md.time_steps=RUNS;
+ md.tau=TAU;
+ md.status=0;
+ md.visual=&vis;
+ md.write=WRITE_FILE;
+
+ lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI;
+ help=lj.sigma6*lj.sigma6;
+ lj.sigma6*=help;
+ lj.sigma12=lj.sigma6*lj.sigma6;
+ lj.epsilon=LJ_EPSILON_SI;
+
+ ho.equilibrium_distance=0.3e-9;
+ ho.spring_constant=1.0e-9;
+
+ u=get_e_pot(&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,t));
+
+
+ /*
+ * let's do the actual md algorithm now
+ *
+ * integration of newtons equations
+ */
+
+ moldyn_integrate(&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);