printf("initializing linked cells (%d)\n",lc->cells);
for(i=0;i<lc->cells;i++)
- list_init(&(lc->subcell[i]),1);
- //list_init(&(lc->subcell[i]),lc->listfd);
+ //list_init(&(lc->subcell[i]),1);
+ list_init(&(lc->subcell[i]),lc->listfd);
link_cell_update(moldyn);
cell[0]=lc->subcell[i+j*nx+k*a];
- printf("%d\n",i+j*nx+k*a);
for(ci=-1;ci<=1;ci++) {
bx=0;
x=i+ci;
bz=1;
}
if(!(ci|cj|ck)) continue;
- printf(" %d %d %d \n",x,y,z);
if(bx|by|bz) {
cell[--count2]=lc->subcell[x+y*nx+z*a];
- printf("%d\n",x+y*nx+z*a);
- printf("--- %d\n",count2);
}
else {
cell[count1++]=lc->subcell[x+y*nx+z*a];
- printf("%d\n",x+y*nx+z*a);
- printf("--- %d\n",count1);
}
}
}
int fd;
char fb[128];
+ /* initialize linked cell method */
+ link_cell_init(moldyn);
+
/* logging & visualization */
e=moldyn->ewrite;
m=moldyn->mwrite;
for(i=0;i<moldyn->time_steps;i++) {
- /* neighbour list update */
- link_cell_update(moldyn);
-
/* integration step */
moldyn->integrate(moldyn);
v3_add(&(atom[i].v),&(atom[i].v),&delta);
}
+ /* neighbour list update */
+ link_cell_update(moldyn);
+
/* forces depending on chosen potential */
moldyn->potential_force_function(moldyn);
equi_dist=params->equilibrium_distance;
count=moldyn->count;
+ /* reset energy counter */
u=0.0;
+
for(i=0;i<count;i++) {
+ /* reset force */
+ v3_zero(&(atom[i].f));
+
/* determine cell + neighbours */
ni=(atom[i].r.x+(moldyn->dim.x/2))/lc->x;
nj=(atom[i].r.y+(moldyn->dim.y/2))/lc->y;
nk=(atom[i].r.z+(moldyn->dim.z/2))/lc->z;
- printf("%d %d %d\n",ni,nj,nk);
c=link_cell_neighbour_index(moldyn,ni,nj,nk,neighbour);
- /* processing cell of atom i */
+ /*
+ * processing cell of atom i
+ * => no need to check for empty list (1 element at minimum)
+ */
this=&(neighbour[0]);
- list_reset(this); /* list has 1 element at minimum */
+ list_reset(this);
do {
btom=this->current->data;
if(btom==&(atom[i]))
continue;
v3_sub(&distance,&(atom[i].r),&(btom->r));
d=v3_norm(&distance);
- u+=(0.5*sc*(d-equi_dist)*(d-equi_dist));
- v3_scale(&force,&distance,-sc*(1.0-(equi_dist/d)));
- v3_add(&(atom[i].f),&(atom[i].f),&force);
+ if(d<=moldyn->cutoff) {
+ u+=(0.5*sc*(d-equi_dist)*(d-equi_dist));
+ v3_scale(&force,&distance,
+ -sc*(1.0-(equi_dist/d)));
+ v3_add(&(atom[i].f),&(atom[i].f),&force);
+ }
} while(list_next(this)!=L_NO_NEXT_ELEMENT);
- /* neighbours not doing boundary condition overflow */
+ /*
+ * direct neighbour cells
+ * => no boundary condition check necessary
+ */
for(j=1;j<c;j++) {
this=&(neighbour[j]);
list_reset(this); /* there might not be a single atom */
}
}
- /* neighbours due to boundary conditions */
+ /*
+ * indirect neighbour cells
+ * => check boundary conditions
+ */
for(j=c;j<27;j++) {
this=&(neighbour[j]);
list_reset(this); /* check boundary conditions */
}
}
- moldyn->energy=u;
+ moldyn->energy=0.5*u;
return 0;
}
sig6=params->sigma6;
sig12=params->sigma12;
+ /* reset energy counter */
u=0.0;
+
for(i=0;i<count;i++) {
+ /* reset force */
+ v3_zero(&(atom[i].f));
+
/* determine cell + neighbours */
ni=(atom[i].r.x+(moldyn->dim.x/2))/lc->x;
nj=(atom[i].r.y+(moldyn->dim.y/2))/lc->y;
nk=(atom[i].r.z+(moldyn->dim.z/2))/lc->z;
- printf("hier atom = %08x\n",&(atom[i]));
c=link_cell_neighbour_index(moldyn,ni,nj,nk,neighbour);
- printf("da atom = %08x\n",&(atom[i]));
- printf("da atom = %08x\n",&(moldyn->atom[i]));
-
- printf("c = %d (%d %d %d)\n",c,ni,nj,nk);
/* processing cell of atom i */
this=&(neighbour[0]);
btom=this->current->data;
if(btom==&(atom[i]))
continue;
- puts("foo");
v3_sub(&distance,&(atom[i].r),&(btom->r));
- puts("foo");
- d=1.0/v3_absolute_square(&distance); /* 1/r^2 */
- h1=d*d; /* 1/r^4 */
- h2*=d; /* 1/r^6 */
- h1=h2*h2; /* 1/r^12 */
- u+=eps*(sig12*h1-sig6*h2);
- h2*=d; /* 1/r^8 */
- h1*=d; /* 1/r^14 */
- h2*=6*sig6;
- h1*=12*sig12;
- d=-h1+h2;
- d*=eps;
- v3_scale(&force,&distance,d);
- v3_add(&(atom[i].f),&(atom[i].f),&force);
- printf("test!!\n");
+ d=v3_absolute_square(&distance); /* 1/r^2 */
+ if(d<=moldyn->cutoff_square) {
+ d=1.0/d; /* 1/r^2 */
+ h1=d*d; /* 1/r^4 */
+ h2*=d; /* 1/r^6 */
+ h1=h2*h2; /* 1/r^12 */
+ u+=eps*(sig12*h1-sig6*h2);
+ h2*=d; /* 1/r^8 */
+ h1*=d; /* 1/r^14 */
+ h2*=6*sig6;
+ h1*=12*sig12;
+ d=-h1+h2;
+ d*=eps;
+ v3_scale(&force,&distance,d);
+ v3_add(&(atom[i].f),&(atom[i].f),&force);
+ }
} while(list_next(this)!=L_NO_NEXT_ELEMENT);
/* neighbours not doing boundary condition overflow */
if(this->start!=NULL) {
do {
- printf("in bound: %d\n",j);
btom=this->current->data;
v3_sub(&distance,&(atom[i].r),&(btom->r));
d=v3_absolute_square(&distance); /* r^2 */
if(this->start!=NULL) {
do {
- printf("out bound: %d\n",j);
btom=this->current->data;
v3_sub(&distance,&(atom[i].r),&(btom->r));
v3_per_bound(&distance,&(moldyn->dim));
}
}
- moldyn->energy=u;
+ moldyn->energy=0.5*u;
return 0;
}
lj.sigma12=lj.sigma6*lj.sigma6;
lj.epsilon4=4.0*LJ_EPSILON_SI;
ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
- ho.spring_constant=1.0;
+ ho.spring_constant=1;
/* assignement */
md.potential_force_function=lennard_jones;
//md.potential_force_function=harmonic_oscillator;
md.count=create_lattice(DIAMOND,SI,M_SI,LC_SI,a,b,c,&(md.atom));
printf("created silicon lattice (#atoms = %d)\n",md.count);
#else
- md.count=2;
- md.atom=malloc(2*sizeof(t_atom));
- md.atom[0].r.x=0.13*sqrt(3.0)*LC_SI/2.0;
+ md.count=3;
+ md.atom=malloc(md.count*sizeof(t_atom));
+ md.atom[0].r.x=0.21*sqrt(3.0)*LC_SI/2.0;
md.atom[0].r.y=0;
md.atom[0].r.z=0;
md.atom[0].element=SI;
md.atom[1].r.z=0;
md.atom[1].element=SI;
md.atom[1].mass=M_SI;
+
+ md.atom[2].r.x=0.5*(a-1)*LC_SI;
+ md.atom[2].r.y=0.5*(b-1)*LC_SI;
+ md.atom[2].r.z=0;
+ md.atom[2].element=C;
+ md.atom[2].mass=M_C;
+
+ //md.atom[3].r.x=0.5*(a-1)*LC_SI;
+ //md.atom[3].r.y=0;
+ //md.atom[3].r.z=0;
+ //md.atom[3].element=SI;
+ //md.atom[3].mass=M_SI;
#endif
/* initial thermal fluctuations of particles */
thermal_init(&md);
#else
for(a=0;a<md.count;a++) v3_zero(&(md.atom[0].v));
+ md.atom[2].v.x=-320;
+ md.atom[2].v.y=-320;
#endif
/* check kinetic energy */
printf("estimated accurate time step: %.30f [s]\n",
estimate_time_step(&md,3.0,md.t));
- /* initialize linked list / cell method */
- link_cell_init(&md);
-
/*
* let's do the actual md algorithm now
*