add another way of calculating tersoff + small moldyn mods
[physik/posic.git] / moldyn.c
index 1ab88eb..4d73617 100644 (file)
--- a/moldyn.c
+++ b/moldyn.c
@@ -82,7 +82,7 @@ int set_pressure(t_moldyn *moldyn,double p_ref) {
 
        moldyn->p_ref=p_ref;
 
-       printf("[moldyn] pressure [atm]: %f\n",moldyn->p_ref/ATM);
+       printf("[moldyn] pressure [bar]: %f\n",moldyn->p_ref/BAR);
 
        return 0;
 }
@@ -162,34 +162,58 @@ int set_pbc(t_moldyn *moldyn,u8 x,u8 y,u8 z) {
        return 0;
 }
 
-int set_potential1b(t_moldyn *moldyn,pf_func1b func,void *params) {
+int set_potential1b(t_moldyn *moldyn,pf_func1b func) {
 
        moldyn->func1b=func;
-       moldyn->pot1b_params=params;
 
        return 0;
 }
 
-int set_potential2b(t_moldyn *moldyn,pf_func2b func,void *params) {
+int set_potential2b(t_moldyn *moldyn,pf_func2b func) {
 
        moldyn->func2b=func;
-       moldyn->pot2b_params=params;
 
        return 0;
 }
 
-int set_potential2b_post(t_moldyn *moldyn,pf_func2b_post func,void *params) {
+int set_potential3b_j1(t_moldyn *moldyn,pf_func2b func) {
 
-       moldyn->func2b_post=func;
-       moldyn->pot2b_params=params;
+       moldyn->func3b_j1=func;
 
        return 0;
 }
 
-int set_potential3b(t_moldyn *moldyn,pf_func3b func,void *params) {
+int set_potential3b_j2(t_moldyn *moldyn,pf_func2b func) {
 
-       moldyn->func3b=func;
-       moldyn->pot3b_params=params;
+       moldyn->func3b_j2=func;
+
+       return 0;
+}
+
+int set_potential3b_j3(t_moldyn *moldyn,pf_func2b func) {
+
+       moldyn->func3b_j3=func;
+
+       return 0;
+}
+
+int set_potential3b_k1(t_moldyn *moldyn,pf_func3b func) {
+
+       moldyn->func3b_k1=func;
+
+       return 0;
+}
+
+int set_potential3b_k2(t_moldyn *moldyn,pf_func3b func) {
+
+       moldyn->func3b_k2=func;
+
+       return 0;
+}
+
+int set_potential_params(t_moldyn *moldyn,void *params) {
+
+       moldyn->pot_params=params;
 
        return 0;
 }
@@ -243,6 +267,32 @@ int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer) {
                        dprintf(moldyn->efd,"# total momentum log file\n");
                        printf("total momentum (%d)\n",timer);
                        break;
+               case LOG_PRESSURE:
+                       moldyn->pwrite=timer;
+                       snprintf(filename,127,"%s/pressure",moldyn->vlsdir);
+                       moldyn->pfd=open(filename,
+                                        O_WRONLY|O_CREAT|O_EXCL,
+                                        S_IRUSR|S_IWUSR);
+                       if(moldyn->pfd<0) {
+                               perror("[moldyn] pressure log file\n");
+                               return moldyn->pfd;
+                       }
+                       dprintf(moldyn->pfd,"# pressure log file\n");
+                       printf("pressure (%d)\n",timer);
+                       break;
+               case LOG_TEMPERATURE:
+                       moldyn->twrite=timer;
+                       snprintf(filename,127,"%s/temperature",moldyn->vlsdir);
+                       moldyn->tfd=open(filename,
+                                        O_WRONLY|O_CREAT|O_EXCL,
+                                        S_IRUSR|S_IWUSR);
+                       if(moldyn->tfd<0) {
+                               perror("[moldyn] temperature log file\n");
+                               return moldyn->tfd;
+                       }
+                       dprintf(moldyn->tfd,"# temperature log file\n");
+                       printf("temperature (%d)\n",timer);
+                       break;
                case SAVE_STEP:
                        moldyn->swrite=timer;
                        printf("save file (%d)\n",timer);
@@ -265,18 +315,52 @@ int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer) {
                                perror("[moldyn] report fd open");      
                                return moldyn->rfd;
                        }
-                       snprintf(filename,127,"%s/plot.scr",moldyn->vlsdir);
-                       moldyn->pfd=open(filename,
-                                        O_WRONLY|O_CREAT|O_EXCL,
-                                        S_IRUSR|S_IWUSR);
-                       if(moldyn->pfd<0) {
-                               perror("[moldyn] plot fd open");
-                               return moldyn->pfd;
+                       printf("report -> ");
+                       if(moldyn->efd) {
+                               snprintf(filename,127,"%s/e_plot.scr",
+                                        moldyn->vlsdir);
+                               moldyn->epfd=open(filename,
+                                                O_WRONLY|O_CREAT|O_EXCL,
+                                                S_IRUSR|S_IWUSR);
+                               if(moldyn->epfd<0) {
+                                       perror("[moldyn] energy plot fd open");
+                                       return moldyn->epfd;
+                               }
+                               dprintf(moldyn->epfd,e_plot_script);
+                               close(moldyn->epfd);
+                               printf("energy ");
+                       }
+                       if(moldyn->pfd) {
+                               snprintf(filename,127,"%s/pressure_plot.scr",
+                                        moldyn->vlsdir);
+                               moldyn->ppfd=open(filename,
+                                                 O_WRONLY|O_CREAT|O_EXCL,
+                                                 S_IRUSR|S_IWUSR);
+                               if(moldyn->ppfd<0) {
+                                       perror("[moldyn] p plot fd open");
+                                       return moldyn->ppfd;
+                               }
+                               dprintf(moldyn->ppfd,pressure_plot_script);
+                               close(moldyn->ppfd);
+                               printf("pressure ");
+                       }
+                       if(moldyn->tfd) {
+                               snprintf(filename,127,"%s/temperature_plot.scr",
+                                        moldyn->vlsdir);
+                               moldyn->tpfd=open(filename,
+                                                 O_WRONLY|O_CREAT|O_EXCL,
+                                                 S_IRUSR|S_IWUSR);
+                               if(moldyn->tpfd<0) {
+                                       perror("[moldyn] t plot fd open");
+                                       return moldyn->tpfd;
+                               }
+                               dprintf(moldyn->tpfd,temperature_plot_script);
+                               close(moldyn->tpfd);
+                               printf("temperature ");
                        }
                        dprintf(moldyn->rfd,report_start,
                                moldyn->rauthor,moldyn->rtitle);
-                       dprintf(moldyn->pfd,plot_script);
-                       close(moldyn->pfd);
+                       printf("\n");
                        break;
                default:
                        printf("unknown log type: %02x\n",type);
@@ -291,13 +375,35 @@ int moldyn_log_shutdown(t_moldyn *moldyn) {
        char sc[256];
 
        printf("[moldyn] log shutdown\n");
-       if(moldyn->efd) close(moldyn->efd);
+       if(moldyn->efd) {
+               close(moldyn->efd);
+               if(moldyn->rfd) {
+                       dprintf(moldyn->rfd,report_energy);
+                       snprintf(sc,255,"cd %s && gnuplot e_plot.scr",
+                                moldyn->vlsdir);
+                       system(sc);
+               }
+       }
        if(moldyn->mfd) close(moldyn->mfd);
+       if(moldyn->pfd) {
+               close(moldyn->pfd);
+               if(moldyn->rfd)
+                       dprintf(moldyn->rfd,report_pressure);
+                       snprintf(sc,255,"cd %s && gnuplot pressure_plot.scr",
+                                moldyn->vlsdir);
+                       system(sc);
+       }
+       if(moldyn->tfd) {
+               close(moldyn->tfd);
+               if(moldyn->rfd)
+                       dprintf(moldyn->rfd,report_temperature);
+                       snprintf(sc,255,"cd %s && gnuplot temperature_plot.scr",
+                                moldyn->vlsdir);
+                       system(sc);
+       }
        if(moldyn->rfd) {
                dprintf(moldyn->rfd,report_end);
                close(moldyn->rfd);
-               snprintf(sc,255,"cd %s && gnuplot plot.scr",moldyn->vlsdir);
-               system(sc);
                snprintf(sc,255,"cd %s && pdflatex report",moldyn->vlsdir);
                system(sc);
                snprintf(sc,255,"cd %s && pdflatex report",moldyn->vlsdir);
@@ -592,6 +698,8 @@ double temperature_calc(t_moldyn *moldyn) {
        /* assume up to date kinetic energy, which is 3/2 N k_B T */
 
        moldyn->t=(2.0*moldyn->ekin)/(3.0*K_BOLTZMANN*moldyn->count);
+       moldyn->t_sum+=moldyn->t;
+       moldyn->mean_t=moldyn->t_sum/moldyn->total_steps;
 
        return moldyn->t;
 }
@@ -673,9 +781,11 @@ double pressure_calc(t_moldyn *moldyn) {
        t_virial *virial;
 
        /*
-        * P = 1/(3V) sum_i ( p_i^2 / 2m + f_i r_i )
-        *
-        * virial = f_i r_i
+        * PV = NkT + <W>
+        * W = 1/3 sum_i f_i r_i
+        * virial = sum_i f_i r_i
+        * 
+        * => P = (2 Ekin + virial) / (3V)
         */
 
        v=0.0;
@@ -687,6 +797,16 @@ double pressure_calc(t_moldyn *moldyn) {
        /* assume up to date kinetic energy */
        moldyn->p=2.0*moldyn->ekin+v;
        moldyn->p/=(3.0*moldyn->volume);
+       moldyn->p_sum+=moldyn->p;
+       moldyn->mean_p=moldyn->p_sum/moldyn->total_steps;
+
+       /* pressure from 'absolute coordinates' virial */
+       virial=&(moldyn->virial);
+       v=virial->xx+virial->yy+virial->zz;
+       moldyn->gp=2.0*moldyn->ekin+v;
+       moldyn->gp/=(3.0*moldyn->volume);
+       moldyn->gp_sum+=moldyn->gp;
+       moldyn->mean_gp=moldyn->gp_sum/moldyn->total_steps;
 
        return moldyn->p;
 }      
@@ -695,9 +815,20 @@ double thermodynamic_pressure_calc(t_moldyn *moldyn) {
 
        t_3dvec dim,*tp;
        double u,p;
-       double scale;
+       double scale,dv;
        t_atom *store;
 
+       /*
+        * dU = - p dV
+        *
+        * => p = - dU/dV
+        *
+        * dV: dx,y,z = 0.001 x,y,z
+        */
+
+       scale=1.00000000000001;
+printf("\n\nP-DEBUG:\n");
+
        tp=&(moldyn->tp);
        store=malloc(moldyn->count*sizeof(t_atom));
        if(store==NULL) {
@@ -711,13 +842,13 @@ double thermodynamic_pressure_calc(t_moldyn *moldyn) {
        dim=moldyn->dim;
 
        /* derivative with respect to x direction */
-       scale=1.0+moldyn->dv/(moldyn->dim.y*moldyn->dim.z);
        scale_dim(moldyn,scale,TRUE,0,0);
        scale_atoms(moldyn,scale,TRUE,0,0);
+       dv=0.00000000000001*moldyn->dim.x*moldyn->dim.y*moldyn->dim.z;
        link_cell_shutdown(moldyn);
        link_cell_init(moldyn,QUIET);
        potential_force_calc(moldyn);
-       tp->x=(moldyn->energy-u)/moldyn->dv;
+       tp->x=(moldyn->energy-u)/dv;
        p=tp->x*tp->x;
 
        /* restore atomic configuration + dim */
@@ -725,13 +856,13 @@ double thermodynamic_pressure_calc(t_moldyn *moldyn) {
        moldyn->dim=dim;
 
        /* derivative with respect to y direction */
-       scale=1.0+moldyn->dv/(moldyn->dim.x*moldyn->dim.z);
        scale_dim(moldyn,scale,0,TRUE,0);
        scale_atoms(moldyn,scale,0,TRUE,0);
+       dv=0.00000000000001*moldyn->dim.y*moldyn->dim.x*moldyn->dim.z;
        link_cell_shutdown(moldyn);
        link_cell_init(moldyn,QUIET);
        potential_force_calc(moldyn);
-       tp->y=(moldyn->energy-u)/moldyn->dv;
+       tp->y=(moldyn->energy-u)/dv;
        p+=tp->y*tp->y;
 
        /* restore atomic configuration + dim */
@@ -739,37 +870,19 @@ double thermodynamic_pressure_calc(t_moldyn *moldyn) {
        moldyn->dim=dim;
 
        /* derivative with respect to z direction */
-       scale=1.0+moldyn->dv/(moldyn->dim.x*moldyn->dim.y);
        scale_dim(moldyn,scale,0,0,TRUE);
        scale_atoms(moldyn,scale,0,0,TRUE);
+       dv=0.00000000000001*moldyn->dim.z*moldyn->dim.x*moldyn->dim.y;
        link_cell_shutdown(moldyn);
        link_cell_init(moldyn,QUIET);
        potential_force_calc(moldyn);
-       tp->z=(moldyn->energy-u)/moldyn->dv;
+       tp->z=(moldyn->energy-u)/dv;
        p+=tp->z*tp->z;
 
        /* restore atomic configuration + dim */
        memcpy(moldyn->atom,store,moldyn->count*sizeof(t_atom));
        moldyn->dim=dim;
 
-       printf("dU/dV komp addiert = %f %f %f\n",tp->x,tp->y,tp->z);
-
-       scale=1.0+pow(moldyn->dv/moldyn->volume,ONE_THIRD);
-
-printf("debug: %f %f\n",moldyn->atom[0].r.x,moldyn->dim.x);
-       scale_dim(moldyn,scale,1,1,1);
-       scale_atoms(moldyn,scale,1,1,1);
-       link_cell_shutdown(moldyn);
-       link_cell_init(moldyn,QUIET);
-       potential_force_calc(moldyn);
-printf("debug: %f %f\n",moldyn->atom[0].r.x,moldyn->dim.x);
-
-       printf("dU/dV einfach = %f\n",((moldyn->energy-u)/moldyn->dv)/ATM);
-
-       /* restore atomic configuration + dim */
-       memcpy(moldyn->atom,store,moldyn->count*sizeof(t_atom));
-       moldyn->dim=dim;
-
        /* restore energy */
        moldyn->energy=u;
 
@@ -863,7 +976,7 @@ moldyn->debug=scale;
 
 }
 
-double get_e_kin(t_moldyn *moldyn) {
+double e_kin_calc(t_moldyn *moldyn) {
 
        int i;
        t_atom *atom;
@@ -877,11 +990,6 @@ double get_e_kin(t_moldyn *moldyn) {
        return moldyn->ekin;
 }
 
-double update_e_kin(t_moldyn *moldyn) {
-
-       return(get_e_kin(moldyn));
-}
-
 double get_total_energy(t_moldyn *moldyn) {
 
        return(moldyn->ekin+moldyn->energy);
@@ -942,7 +1050,12 @@ int link_cell_init(t_moldyn *moldyn,u8 vol) {
        if(lc->cells<27)
                printf("[moldyn] FATAL: less then 27 subcells!\n");
 
-       if(vol) printf("[moldyn] initializing linked cells (%d)\n",lc->cells);
+       if(vol) {
+               printf("[moldyn] initializing linked cells (%d)\n",lc->cells);
+               printf("  x: %d x %f A\n",lc->nx,lc->x);
+               printf("  y: %d x %f A\n",lc->ny,lc->y);
+               printf("  z: %d x %f A\n",lc->nz,lc->z);
+       }
 
        for(i=0;i<lc->cells;i++)
                list_init_f(&(lc->subcell[i]));
@@ -977,7 +1090,7 @@ int link_cell_update(t_moldyn *moldyn) {
                i=((atom[count].r.x+(moldyn->dim.x/2))/lc->x);
                j=((atom[count].r.y+(moldyn->dim.y/2))/lc->y);
                k=((atom[count].r.z+(moldyn->dim.z/2))/lc->z);
-               list_add_immediate_f(&(moldyn->lc.subcell[i+j*nx+k*nx*ny]),
+               list_add_immediate_f(&(lc->subcell[i+j*nx+k*nx*ny]),
                                     &(atom[count]));
        }
 
@@ -1106,14 +1219,15 @@ int moldyn_set_schedule_hook(t_moldyn *moldyn,set_hook hook,void *hook_params) {
 int moldyn_integrate(t_moldyn *moldyn) {
 
        int i;
-       unsigned int e,m,s,v;
-       t_3dvec p;
+       unsigned int e,m,s,v,p,t;
+       t_3dvec momentum;
        t_moldyn_schedule *sched;
        t_atom *atom;
        int fd;
        char dir[128];
        double ds;
        double energy_scale;
+       //double tp;
 
        sched=&(moldyn->schedule);
        atom=moldyn->atom;
@@ -1126,6 +1240,8 @@ int moldyn_integrate(t_moldyn *moldyn) {
        m=moldyn->mwrite;
        s=moldyn->swrite;
        v=moldyn->vwrite;
+       p=moldyn->pwrite;
+       t=moldyn->twrite;
 
        /* sqaure of some variables */
        moldyn->tau_square=moldyn->tau*moldyn->tau;
@@ -1150,6 +1266,7 @@ int moldyn_integrate(t_moldyn *moldyn) {
 
        /* zero absolute time */
        moldyn->time=0.0;
+       moldyn->total_steps=0;
 
        /* debugging, ignore */
        moldyn->debug=0;
@@ -1173,10 +1290,11 @@ int moldyn_integrate(t_moldyn *moldyn) {
                moldyn->integrate(moldyn);
 
                /* calculate kinetic energy, temperature and pressure */
-               update_e_kin(moldyn);
+               e_kin_calc(moldyn);
                temperature_calc(moldyn);
                pressure_calc(moldyn);
-               //thermodynamic_pressure_calc(moldyn);
+               //tp=thermodynamic_pressure_calc(moldyn);
+//printf("thermodynamic p: %f %f %f - %f\n",moldyn->tp.x/BAR,moldyn->tp.y/BAR,moldyn->tp.z/BAR,tp/BAR);
 
                /* p/t scaling */
                if(moldyn->pt_scale&(T_SCALE_BERENDSEN|T_SCALE_DIRECT))
@@ -1195,9 +1313,26 @@ int moldyn_integrate(t_moldyn *moldyn) {
                }
                if(m) {
                        if(!(i%m)) {
-                               p=get_total_p(moldyn);
+                               momentum=get_total_p(moldyn);
                                dprintf(moldyn->mfd,
-                                       "%f %f\n",moldyn->time,v3_norm(&p));
+                                       "%f %f %f %f %f\n",moldyn->time,
+                                       momentum.x,momentum.y,momentum.z,
+                                       v3_norm(&momentum));
+                       }
+               }
+               if(p) {
+                       if(!(i%p)) {
+                               dprintf(moldyn->pfd,
+                                       "%f %f %f %f %f\n",moldyn->time,
+                                        moldyn->p/BAR,moldyn->mean_p/BAR,
+                                        moldyn->gp/BAR,moldyn->mean_gp/BAR);
+                       }
+               }
+               if(t) {
+                       if(!(i%t)) {
+                               dprintf(moldyn->tfd,
+                                       "%f %f %f\n",
+                                       moldyn->time,moldyn->t,moldyn->mean_t);
                        }
                }
                if(s) {
@@ -1218,15 +1353,23 @@ int moldyn_integrate(t_moldyn *moldyn) {
                        if(!(i%v)) {
                                visual_atoms(&(moldyn->vis),moldyn->time,
                                             moldyn->atom,moldyn->count);
-                               printf("\rsched: %d, steps: %d, T: %f, P: %f V: %f",
-                                      sched->count,i,
-                                      moldyn->t,moldyn->p/ATM,moldyn->volume);
-                               fflush(stdout);
                        }
                }
 
+               /* display progress */
+               if(!(i%10)) {
+                       printf("\rsched: %d, steps: %d, T: %f, P: %f %f V: %f",
+                              sched->count,i,
+                              moldyn->mean_t,
+                              moldyn->mean_p/BAR,
+                              moldyn->mean_gp/BAR,
+                              moldyn->volume);
+                       fflush(stdout);
+               }
+
                /* increase absolute time */
                moldyn->time+=moldyn->tau;
+               moldyn->total_steps+=1;
 
        }
 
@@ -1313,6 +1456,9 @@ int potential_force_calc(t_moldyn *moldyn) {
        /* reset energy */
        moldyn->energy=0.0;
 
+       /* reset global virial */
+       memset(&(moldyn->virial),0,sizeof(t_virial));
+
        /* reset force, site energy and virial of every atom */
        for(i=0;i<count;i++) {
 
@@ -1333,7 +1479,9 @@ int potential_force_calc(t_moldyn *moldyn) {
 
        }
 
-       /* get energy,force and virial of every atom */
+       /* get energy, force and virial of every atom */
+
+       /* first (and only) loop over atoms i */
        for(i=0;i<count;i++) {
 
                /* single particle potential/force */
@@ -1353,6 +1501,45 @@ int potential_force_calc(t_moldyn *moldyn) {
 
                dnlc=lc->dnlc;
 
+               /* first loop over atoms j */
+               if(moldyn->func2b) {
+                       for(j=0;j<27;j++) {
+
+                               this=&(neighbour_i[j]);
+                               list_reset_f(this);
+
+                               if(this->start==NULL)
+                                       continue;
+
+                               bc_ij=(j<dnlc)?0:1;
+
+                               do {
+                                       jtom=this->current->data;
+
+                                       if(jtom==&(itom[i]))
+                                               continue;
+
+                                       if((jtom->attr&ATOM_ATTR_2BP)&
+                                          (itom[i].attr&ATOM_ATTR_2BP)) {
+                                               moldyn->func2b(moldyn,
+                                                              &(itom[i]),
+                                                              jtom,
+                                                              bc_ij);
+                                       }
+                               } while(list_next_f(this)!=L_NO_NEXT_ELEMENT);
+
+                       }
+               }
+
+               /* 3 body potential/force */
+
+               if(!(itom[i].attr&ATOM_ATTR_3BP))
+                       continue;
+
+               /* copy the neighbour lists */
+               memcpy(neighbour_i2,neighbour_i,27*sizeof(t_list));
+
+               /* second loop over atoms j */
                for(j=0;j<27;j++) {
 
                        this=&(neighbour_i[j]);
@@ -1369,25 +1556,70 @@ int potential_force_calc(t_moldyn *moldyn) {
                                if(jtom==&(itom[i]))
                                        continue;
 
-                               if((jtom->attr&ATOM_ATTR_2BP)&
-                                  (itom[i].attr&ATOM_ATTR_2BP)) {
-                                       moldyn->func2b(moldyn,
-                                                      &(itom[i]),
-                                                      jtom,
-                                                      bc_ij);
-                               }
+                               if(!(jtom->attr&ATOM_ATTR_3BP))
+                                       continue;
 
-                               /* 3 body potential/force */
+                               /* reset 3bp run */
+                               moldyn->run3bp=1;
 
-                               if(!(itom[i].attr&ATOM_ATTR_3BP)||
-                                  !(jtom->attr&ATOM_ATTR_3BP))
+                               if(moldyn->func3b_j1)
+                                       moldyn->func3b_j1(moldyn,
+                                                         &(itom[i]),
+                                                         jtom,
+                                                         bc_ij);
+
+                               /* in first j loop, 3bp run can be skipped */
+                               if(!(moldyn->run3bp))
                                        continue;
+                       
+                               /* first loop over atoms k */
+                               if(moldyn->func3b_k1) {
+
+                               for(k=0;k<27;k++) {
+
+                                       that=&(neighbour_i2[k]);
+                                       list_reset_f(that);
+                                       
+                                       if(that->start==NULL)
+                                               continue;
+
+                                       bc_ik=(k<dnlc)?0:1;
+
+                                       do {
+
+                                               ktom=that->current->data;
+
+                                               if(!(ktom->attr&ATOM_ATTR_3BP))
+                                                       continue;
+
+                                               if(ktom==jtom)
+                                                       continue;
+
+                                               if(ktom==&(itom[i]))
+                                                       continue;
+
+                                               moldyn->func3b_k1(moldyn,
+                                                                 &(itom[i]),
+                                                                 jtom,
+                                                                 ktom,
+                                                                 bc_ik|bc_ij);
+
+                                       } while(list_next_f(that)!=\
+                                               L_NO_NEXT_ELEMENT);
+
+                               }
+
+                               }
 
-                               /* copy the neighbour lists */
-                               memcpy(neighbour_i2,neighbour_i,
-                                      27*sizeof(t_list));
+                               if(moldyn->func3b_j2)
+                                       moldyn->func3b_j2(moldyn,
+                                                         &(itom[i]),
+                                                         jtom,
+                                                         bc_ij);
+
+                               /* second loop over atoms k */
+                               if(moldyn->func3b_k2) {
 
-                               /* get neighbours of i */
                                for(k=0;k<27;k++) {
 
                                        that=&(neighbour_i2[k]);
@@ -1411,37 +1643,53 @@ int potential_force_calc(t_moldyn *moldyn) {
                                                if(ktom==&(itom[i]))
                                                        continue;
 
-                                               moldyn->func3b(moldyn,
-                                                              &(itom[i]),
-                                                              jtom,
-                                                              ktom,
-                                                              bc_ik|bc_ij);
+                                               moldyn->func3b_k2(moldyn,
+                                                                 &(itom[i]),
+                                                                 jtom,
+                                                                 ktom,
+                                                                 bc_ik|bc_ij);
 
                                        } while(list_next_f(that)!=\
                                                L_NO_NEXT_ELEMENT);
 
                                }
+                               
+                               }
 
                                /* 2bp post function */
-                               if(moldyn->func2b_post) {
-                                       moldyn->func2b_post(moldyn,
-                                                           &(itom[i]),
-                                                           jtom,bc_ij);
+                               if(moldyn->func3b_j3) {
+                                       moldyn->func3b_j3(moldyn,
+                                                         &(itom[i]),
+                                                         jtom,bc_ij);
                                }
                                        
                        } while(list_next_f(this)!=L_NO_NEXT_ELEMENT);
                
                }
+               
+#ifdef DEBUG
+       //printf("\n\n");
+#endif
+#ifdef VDEBUG
+       printf("\n\n");
+#endif
 
        }
 
 #ifdef DEBUG
-printf("\n\n");
-#endif
-#ifdef VDEBUG
-printf("\n\n");
+       printf("\nATOM 0: %f %f %f\n\n",itom->f.x,itom->f.y,itom->f.z);
 #endif
 
+       /* calculate global virial */
+       for(i=0;i<count;i++) {
+               moldyn->virial.xx+=moldyn->atom[i].r.x*moldyn->atom[i].f.x;
+               moldyn->virial.yy+=moldyn->atom[i].r.y*moldyn->atom[i].f.y;
+               moldyn->virial.zz+=moldyn->atom[i].r.z*moldyn->atom[i].f.z;
+               moldyn->virial.xy+=moldyn->atom[i].r.y*moldyn->atom[i].f.x;
+               moldyn->virial.xz+=moldyn->atom[i].r.z*moldyn->atom[i].f.x;
+               moldyn->virial.yz+=moldyn->atom[i].r.z*moldyn->atom[i].f.y;
+       }
+
        return 0;
 }
 
@@ -1449,7 +1697,8 @@ printf("\n\n");
  * virial calculation
  */
 
-inline int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d) {
+//inline int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d) {
+int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d) {
 
        a->virial.xx+=f->x*d->x;
        a->virial.yy+=f->y*d->y;
@@ -1465,7 +1714,8 @@ inline int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d) {
  * periodic boundayr checking
  */
 
-inline int check_per_bound(t_moldyn *moldyn,t_3dvec *a) {
+//inline int check_per_bound(t_moldyn *moldyn,t_3dvec *a) {
+int check_per_bound(t_moldyn *moldyn,t_3dvec *a) {
        
        double x,y,z;
        t_3dvec *dim;
@@ -1492,45 +1742,6 @@ inline int check_per_bound(t_moldyn *moldyn,t_3dvec *a) {
        return 0;
 }
         
-
-/*
- * example potentials
- */
-
-/* harmonic oscillator potential and force */
-
-int harmonic_oscillator(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
-
-       t_ho_params *params;
-       t_3dvec force,distance;
-       double d,f;
-       double sc,equi_dist;
-
-       params=moldyn->pot2b_params;
-       sc=params->spring_constant;
-       equi_dist=params->equilibrium_distance;
-
-       if(ai<aj) return 0;
-
-       v3_sub(&distance,&(aj->r),&(ai->r));
-       
-       if(bc) check_per_bound(moldyn,&distance);
-       d=v3_norm(&distance);
-       if(d<=moldyn->cutoff) {
-               moldyn->energy+=(0.5*sc*(d-equi_dist)*(d-equi_dist));
-               /* f = -grad E; grad r_ij = -1 1/r_ij distance */
-               f=sc*(1.0-equi_dist/d);
-               v3_scale(&force,&distance,f);
-               v3_add(&(ai->f),&(ai->f),&force);
-               virial_calc(ai,&force,&distance);
-               virial_calc(aj,&force,&distance); /* f and d signe switched */
-               v3_scale(&force,&distance,-f);
-               v3_add(&(aj->f),&(aj->f),&force);
-       }
-
-       return 0;
-}
-
 /*
  * debugging / critical check functions
  */