runtime schedule adding and injection of c atoms
[physik/posic.git] / moldyn.c
index 94d596e..433be68 100644 (file)
--- a/moldyn.c
+++ b/moldyn.c
@@ -16,6 +16,7 @@
 #include <math.h>
 
 #include "moldyn.h"
+#include "report/report.h"
 
 int moldyn_init(t_moldyn *moldyn,int argc,char **argv) {
 
@@ -72,7 +73,7 @@ int set_temperature(t_moldyn *moldyn,double t_ref) {
 
        moldyn->t_ref=t_ref;
 
-       printf("[moldyn] temperature: %f\n",moldyn->t_ref);
+       printf("[moldyn] temperature [K]: %f\n",moldyn->t_ref);
 
        return 0;
 }
@@ -81,7 +82,7 @@ int set_pressure(t_moldyn *moldyn,double p_ref) {
 
        moldyn->p_ref=p_ref;
 
-       printf("[moldyn] pressure: %f\n",moldyn->p_ref);
+       printf("[moldyn] pressure [bar]: %f\n",moldyn->p_ref/BAR);
 
        return 0;
 }
@@ -121,7 +122,7 @@ int set_dim(t_moldyn *moldyn,double x,double y,double z,u8 visualize) {
                moldyn->vis.dim.z=z;
        }
 
-       moldyn->dv=0.0001*moldyn->volume;
+       moldyn->dv=0.000001*moldyn->volume;
 
        printf("[moldyn] dimensions in A and A^3 respectively:\n");
        printf("  x: %f\n",moldyn->dim.x);
@@ -161,34 +162,66 @@ 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;
+}
+
+int set_avg_skip(t_moldyn *moldyn,int skip) {
+
+       printf("[moldyn] skip %d steps before starting average calc\n",skip);
+       moldyn->avg_skip=skip;
 
        return 0;
 }
@@ -199,6 +232,14 @@ int moldyn_set_log_dir(t_moldyn *moldyn,char *dir) {
 
        return 0;
 }
+
+int moldyn_set_report(t_moldyn *moldyn,char *author,char *title) {
+
+       strncpy(moldyn->rauthor,author,63);
+       strncpy(moldyn->rtitle,title,63);
+
+       return 0;
+}
        
 int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer) {
 
@@ -234,6 +275,32 @@ 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);
@@ -247,6 +314,62 @@ int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer) {
                        }
                        printf("visual file (%d)\n",timer);
                        break;
+               case CREATE_REPORT:
+                       snprintf(filename,127,"%s/report.tex",moldyn->vlsdir);
+                       moldyn->rfd=open(filename,
+                                        O_WRONLY|O_CREAT|O_EXCL,
+                                        S_IRUSR|S_IWUSR);
+                       if(moldyn->rfd<0) {
+                               perror("[moldyn] report fd open");      
+                               return moldyn->rfd;
+                       }
+                       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);
+                       printf("\n");
+                       break;
                default:
                        printf("unknown log type: %02x\n",type);
                        return -1;
@@ -257,9 +380,48 @@ int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer) {
 
 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 && pdflatex report >/dev/null 2>&1",
+                        moldyn->vlsdir);
+               system(sc);
+               snprintf(sc,255,"cd %s && pdflatex report >/dev/null 2>&1",
+                        moldyn->vlsdir);
+               system(sc);
+               snprintf(sc,255,"cd %s && dvipdf report >/dev/null 2>&1",
+                        moldyn->vlsdir);
+               system(sc);
+       }
        if(&(moldyn->vis)) visual_tini(&(moldyn->vis));
 
        return 0;
@@ -270,11 +432,11 @@ int moldyn_log_shutdown(t_moldyn *moldyn) {
  */
 
 int create_lattice(t_moldyn *moldyn,u8 type,double lc,int element,double mass,
-                   u8 attr,u8 brand,int a,int b,int c) {
+                   u8 attr,u8 brand,int a,int b,int c,t_3dvec *origin) {
 
        int new,count;
        int ret;
-       t_3dvec origin;
+       t_3dvec orig;
        void *ptr;
        t_atom *atom;
 
@@ -294,18 +456,35 @@ int create_lattice(t_moldyn *moldyn,u8 type,double lc,int element,double mass,
        }
        moldyn->atom=ptr;
        atom=&(moldyn->atom[count]);
-               
-       v3_zero(&origin);
+
+       /* no atoms on the boundaries (only reason: it looks better!) */
+       if(!origin) {
+               orig.x=0.5*lc;
+               orig.y=0.5*lc;
+               orig.z=0.5*lc;
+       }
+       else {
+               orig.x=origin->x;
+               orig.y=origin->y;
+               orig.z=origin->z;
+       }
 
        switch(type) {
                case CUBIC:
-                       ret=cubic_init(a,b,c,atom,&origin);
+                       set_nn_dist(moldyn,lc);
+                       ret=cubic_init(a,b,c,lc,atom,&orig);
                        break;
                case FCC:
-                       ret=fcc_init(a,b,c,lc,atom,&origin);
+                       if(!origin)
+                               v3_scale(&orig,&orig,0.5);
+                       set_nn_dist(moldyn,0.5*sqrt(2.0)*lc);
+                       ret=fcc_init(a,b,c,lc,atom,&orig);
                        break;
                case DIAMOND:
-                       ret=diamond_init(a,b,c,lc,atom,&origin);
+                       if(!origin)
+                               v3_scale(&orig,&orig,0.25);
+                       set_nn_dist(moldyn,0.25*sqrt(3.0)*lc);
+                       ret=diamond_init(a,b,c,lc,atom,&orig);
                        break;
                default:
                        printf("unknown lattice type (%02x)\n",type);
@@ -333,6 +512,9 @@ int create_lattice(t_moldyn *moldyn,u8 type,double lc,int element,double mass,
                check_per_bound(moldyn,&(atom[ret].r));
        }
 
+       /* update total system mass */
+       total_mass_calc(moldyn);
+
        return ret;
 }
 
@@ -340,74 +522,93 @@ int create_lattice(t_moldyn *moldyn,u8 type,double lc,int element,double mass,
 int cubic_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin) {
 
        int count;
-       t_3dvec r
+       t_3dvec r;
+       int i,j,k;
+       t_3dvec o;
+
+       count=0;
+       if(origin)
+               v3_copy(&o,origin);
+       else
+               v3_zero(&o);
+
+       r.x=o.x;
+       for(i=0;i<a;i++) {
+               r.y=o.y;
+               for(j=0;j<b;j++) {
+                       r.z=o.z;
+                       for(k=0;k<c;k++) {
+                               v3_copy(&(atom[count].r),&r);
+                               count+=1;
+                               r.z+=lc;
+                       }
+                       r.y+=lc;
+               }
+               r.x+=lc;
+       }
+
+       for(i=0;i<count;i++) {
+               atom[i].r.x-=(a*lc)/2.0;
+               atom[i].r.y-=(b*lc)/2.0;
+               atom[i].r.z-=(c*lc)/2.0;
+       }
 
-HIER WEITER !
+       return count;
 }
 
 /* fcc lattice init */
 int fcc_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin) {
 
        int count;
-       int i,j;
+       int i,j,k,l;
        t_3dvec o,r,n;
        t_3dvec basis[3];
-       double help[3];
-       double x,y,z;
-
-       x=a*lc;
-       y=b*lc;
-       z=c*lc;
 
-       if(origin) v3_copy(&o,origin);
-       else v3_zero(&o);
+       count=0;
+       if(origin)
+               v3_copy(&o,origin);
+       else
+               v3_zero(&o);
 
        /* construct the basis */
-       for(i=0;i<3;i++) {
-               for(j=0;j<3;j++) {
-                       if(i!=j) help[j]=0.5*lc;
-                       else help[j]=.0;
-               }
-               v3_set(&basis[i],help);
-       }
+       memset(basis,0,3*sizeof(t_3dvec));
+       basis[0].x=0.5*lc;
+       basis[0].y=0.5*lc;
+       basis[1].x=0.5*lc;
+       basis[1].z=0.5*lc;
+       basis[2].y=0.5*lc;
+       basis[2].z=0.5*lc;
 
-       v3_zero(&r);
-       count=0;
-       
        /* fill up the room */
        r.x=o.x;
-       while(r.x<x) {
+       for(i=0;i<a;i++) {
                r.y=o.y;
-               while(r.y<y) {
+               for(j=0;j<b;j++) {
                        r.z=o.z;
-                       while(r.z<z) {
+                       for(k=0;k<c;k++) {
+                               /* first atom */
                                v3_copy(&(atom[count].r),&r);
-                               atom[count].element=1;
                                count+=1;
-                               for(i=0;i<3;i++) {
-                                       v3_add(&n,&r,&basis[i]);
-                                       if((n.x<x+o.x)&&
-                                          (n.y<y+o.y)&&
-                                          (n.z<z+o.z)) {
-                                               v3_copy(&(atom[count].r),&n);
-                                               count+=1;
-                                       }
+                               r.z+=lc;
+                               /* the three face centered atoms */
+                               for(l=0;l<3;l++) {
+                                       v3_add(&n,&r,&basis[l]);
+                                       v3_copy(&(atom[count].r),&n);
+                                       count+=1;
                                }
-                               r.z+=lc;        
                        }
                        r.y+=lc;
                }
                r.x+=lc;
        }
-
+                               
        /* coordinate transformation */
-       help[0]=x/2.0;
-       help[1]=y/2.0;
-       help[2]=z/2.0;
-       v3_set(&n,help);
-       for(i=0;i<count;i++)
-               v3_sub(&(atom[i].r),&(atom[i].r),&n);
-               
+       for(i=0;i<count;i++) {
+               atom[i].r.x-=(a*lc)/2.0;
+               atom[i].r.y-=(b*lc)/2.0;
+               atom[i].r.z-=(c*lc)/2.0;
+       }
+
        return count;
 }
 
@@ -455,6 +656,9 @@ int add_atom(t_moldyn *moldyn,int element,double mass,u8 brand,u8 attr,
        atom[count].tag=count;
        atom[count].attr=attr;
 
+       /* update total system mass */
+       total_mass_calc(moldyn);
+
        return 0;
 }
 
@@ -515,20 +719,23 @@ int thermal_init(t_moldyn *moldyn,u8 equi_init) {
        return 0;
 }
 
-double temperature_calc(t_moldyn *moldyn) {
+double total_mass_calc(t_moldyn *moldyn) {
 
-       double double_ekin;
        int i;
-       t_atom *atom;
 
-       atom=moldyn->atom;
+       moldyn->mass=0.0;
 
-       double_ekin=0;
        for(i=0;i<moldyn->count;i++)
-               double_ekin+=atom[i].mass*v3_absolute_square(&(atom[i].v));
+               moldyn->mass+=moldyn->atom[i].mass;
+
+       return moldyn->mass;
+}
+
+double temperature_calc(t_moldyn *moldyn) {
+
+       /* assume up to date kinetic energy, which is 3/2 N k_B T */
 
-       /* kinetic energy = 3/2 N k_B T */
-       moldyn->t=double_ekin/(3.0*K_BOLTZMANN*moldyn->count);
+       moldyn->t=(2.0*moldyn->ekin)/(3.0*K_BOLTZMANN*moldyn->count);
 
        return moldyn->t;
 }
@@ -599,47 +806,146 @@ double ideal_gas_law_pressure(t_moldyn *moldyn) {
        double p;
 
        p=moldyn->count*moldyn->t*K_BOLTZMANN/moldyn->volume;
-printf("temp = %f => ideal gas law pressure: %f\n",moldyn->t,p/ATM);
 
        return p;
 }
 
-double pressure_calc(t_moldyn *moldyn) {
+double virial_sum(t_moldyn *moldyn) {
 
        int i;
-       double p1,p;
-       double v,h;
+       double v;
        t_virial *virial;
 
+       /* virial (sum over atom virials) */
        v=0.0;
        for(i=0;i<moldyn->count;i++) {
                virial=&(moldyn->atom[i].virial);
                v+=(virial->xx+virial->yy+virial->zz);
        }
+       moldyn->virial=v;
+
+       /* global virial (absolute coordinates) */
+       virial=&(moldyn->gvir);
+       moldyn->gv=virial->xx+virial->yy+virial->zz;
+
+       return moldyn->virial;
+}
 
-       h=moldyn->count*K_BOLTZMANN*moldyn->t;
+double pressure_calc(t_moldyn *moldyn) {
 
-       p=(h-ONE_THIRD*v);
-       p/=moldyn->volume;
+       /*
+        * PV = NkT + <W>
+        * with W = 1/3 sum_i f_i r_i (- skipped!)
+        * virial = sum_i f_i r_i
+        * 
+        * => P = (2 Ekin + virial) / (3V)
+        */
 
-       p1=(moldyn->count*K_BOLTZMANN*moldyn->t-ONE_THIRD*moldyn->vt1);
-       p1/=moldyn->volume;
+       /* assume up to date virial & up to date kinetic energy */
 
-       printf("debug: vt1=%f v=%f nkt=%f\n",moldyn->vt1,v,h);
+       /* pressure (atom virials) */
+       moldyn->p=2.0*moldyn->ekin+moldyn->virial;
+       moldyn->p/=(3.0*moldyn->volume);
 
-       printf("compare pressures: %f %f %f\n",p1/ATM,p/ATM,h/moldyn->volume/ATM);
+       /* pressure (absolute coordinates) */
+       moldyn->gp=2.0*moldyn->ekin+moldyn->gv;
+       moldyn->gp/=(3.0*moldyn->volume);
 
        return moldyn->p;
-}      
+}
+
+int average_and_fluctuation_calc(t_moldyn *moldyn) {
+
+       if(moldyn->total_steps<moldyn->avg_skip)
+               return 0;
+
+       int denom=moldyn->total_steps+1-moldyn->avg_skip;
+
+       /* assume up to date energies, temperature, pressure etc */
+
+       /* kinetic energy */
+       moldyn->k_sum+=moldyn->ekin;
+       moldyn->k2_sum+=(moldyn->ekin*moldyn->ekin);
+       moldyn->k_avg=moldyn->k_sum/denom;
+       moldyn->k2_avg=moldyn->k2_sum/denom;
+       moldyn->dk2_avg=moldyn->k2_avg-(moldyn->k_avg*moldyn->k_avg);
+
+       /* potential energy */
+       moldyn->v_sum+=moldyn->energy;
+       moldyn->v2_sum+=(moldyn->energy*moldyn->energy);
+       moldyn->v_avg=moldyn->v_sum/denom;
+       moldyn->v2_avg=moldyn->v2_sum/denom;
+       moldyn->dv2_avg=moldyn->v2_avg-(moldyn->v_avg*moldyn->v_avg);
+
+       /* temperature */
+       moldyn->t_sum+=moldyn->t;
+       moldyn->t_avg=moldyn->t_sum/denom;
+
+       /* virial */
+       moldyn->virial_sum+=moldyn->virial;
+       moldyn->virial_avg=moldyn->virial_sum/denom;
+       moldyn->gv_sum+=moldyn->gv;
+       moldyn->gv_avg=moldyn->gv_sum/denom;
+
+       /* pressure */
+       moldyn->p_sum+=moldyn->p;
+       moldyn->p_avg=moldyn->p_sum/denom;
+       moldyn->gp_sum+=moldyn->gp;
+       moldyn->gp_avg=moldyn->gp_sum/denom;
+
+       return 0;
+}
+
+int get_heat_capacity(t_moldyn *moldyn) {
+
+       double temp2,ighc;
+
+       /* averages needed for heat capacity calc */
+       if(moldyn->total_steps<moldyn->avg_skip)
+               return 0;
+
+       /* (temperature average)^2 */
+       temp2=moldyn->t_avg*moldyn->t_avg;
+       printf("[moldyn] specific heat capacity for T=%f K [J/(kg K)]\n",
+              moldyn->t_avg);
+
+       /* ideal gas contribution */
+       ighc=3.0*moldyn->count*K_BOLTZMANN/2.0;
+       printf("  ideal gas contribution: %f\n",
+              ighc/moldyn->mass*KILOGRAM/JOULE);
+
+       /* specific heat for nvt ensemble */
+       moldyn->c_v_nvt=moldyn->dv2_avg/(K_BOLTZMANN*temp2)+ighc;
+       moldyn->c_v_nvt/=moldyn->mass;
+
+       /* specific heat for nve ensemble */
+       moldyn->c_v_nve=ighc/(1.0-(moldyn->dv2_avg/(ighc*K_BOLTZMANN*temp2)));
+       moldyn->c_v_nve/=moldyn->mass;
+
+       printf("  NVE: %f\n",moldyn->c_v_nve*KILOGRAM/JOULE);
+       printf("  NVT: %f\n",moldyn->c_v_nvt*KILOGRAM/JOULE);
+printf("  --> <dV2> sim: %f experimental: %f\n",moldyn->dv2_avg,1.5*moldyn->count*K_B2*moldyn->t_avg*moldyn->t_avg*(1.0-1.5*moldyn->count*K_BOLTZMANN/(700*moldyn->mass*JOULE/KILOGRAM)));
+
+       return 0;
+}
 
 double thermodynamic_pressure_calc(t_moldyn *moldyn) {
 
        t_3dvec dim,*tp;
-       double u,p;
-       double scale;
+       double u_up,u_down,dv;
+       double scale,p;
        t_atom *store;
 
-       tp=&(moldyn->tp);
+       /*
+        * dU = - p dV
+        *
+        * => p = - dU/dV
+        *
+        */
+
+       scale=0.00001;
+       dv=8*scale*scale*scale*moldyn->volume;
+
        store=malloc(moldyn->count*sizeof(t_atom));
        if(store==NULL) {
                printf("[moldyn] allocating store mem failed\n");
@@ -647,64 +953,44 @@ double thermodynamic_pressure_calc(t_moldyn *moldyn) {
        }
 
        /* save unscaled potential energy + atom/dim configuration */
-       u=moldyn->energy;
        memcpy(store,moldyn->atom,moldyn->count*sizeof(t_atom));
        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);
-       potential_force_calc(moldyn);
-       tp->x=(moldyn->energy-u)/moldyn->dv;
-       p=tp->x*tp->x;
-
-       /* restore atomic configuration + dim */
-       memcpy(moldyn->atom,store,moldyn->count*sizeof(t_atom));
-       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);
+       /* scale up dimension and atom positions */
+       scale_dim(moldyn,SCALE_UP,scale,TRUE,TRUE,TRUE);
+       scale_atoms(moldyn,SCALE_UP,scale,TRUE,TRUE,TRUE);
+       link_cell_shutdown(moldyn);
+       link_cell_init(moldyn,QUIET);
        potential_force_calc(moldyn);
-       tp->y=(moldyn->energy-u)/moldyn->dv;
-       p+=tp->y*tp->y;
+       u_up=moldyn->energy;
 
        /* restore atomic configuration + dim */
        memcpy(moldyn->atom,store,moldyn->count*sizeof(t_atom));
        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);
+       /* scale down dimension and atom positions */
+       scale_dim(moldyn,SCALE_DOWN,scale,TRUE,TRUE,TRUE);
+       scale_atoms(moldyn,SCALE_DOWN,scale,TRUE,TRUE,TRUE);
+       link_cell_shutdown(moldyn);
+       link_cell_init(moldyn,QUIET);
        potential_force_calc(moldyn);
-       tp->z=(moldyn->energy-u)/moldyn->dv;
-       p+=tp->z*tp->z;
+       u_down=moldyn->energy;
+       
+       /* calculate pressure */
+       p=-(u_up-u_down)/dv;
+printf("-------> %.10f %.10f %f\n",u_up/EV/moldyn->count,u_down/EV/moldyn->count,p/BAR);
 
        /* restore atomic configuration + dim */
        memcpy(moldyn->atom,store,moldyn->count*sizeof(t_atom));
        moldyn->dim=dim;
 
-       printf("dU/dV komp addiert = %f\n",(tp->x+tp->y+tp->z)/ATM);
-
-       scale=1.0+pow(moldyn->dv/moldyn->volume,ONE_THIRD);
-
-       scale_dim(moldyn,scale,1,1,1);
-       scale_dim(moldyn,scale,1,1,1);
+       /* restore energy */
        potential_force_calc(moldyn);
 
-       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;
+       link_cell_shutdown(moldyn);
+       link_cell_init(moldyn,QUIET);
 
-       return sqrt(p);
+       return p;
 }
 
 double get_pressure(t_moldyn *moldyn) {
@@ -713,12 +999,18 @@ double get_pressure(t_moldyn *moldyn) {
 
 }
 
-int scale_dim(t_moldyn *moldyn,double scale,u8 x,u8 y,u8 z) {
+int scale_dim(t_moldyn *moldyn,u8 dir,double scale,u8 x,u8 y,u8 z) {
 
        t_3dvec *dim;
 
        dim=&(moldyn->dim);
 
+       if(dir==SCALE_UP)
+               scale=1.0+scale;
+
+       if(dir==SCALE_DOWN)
+               scale=1.0-scale;
+
        if(x) dim->x*=scale;
        if(y) dim->y*=scale;
        if(z) dim->z*=scale;
@@ -726,11 +1018,17 @@ int scale_dim(t_moldyn *moldyn,double scale,u8 x,u8 y,u8 z) {
        return 0;
 }
 
-int scale_atoms(t_moldyn *moldyn,double scale,u8 x,u8 y,u8 z) {
+int scale_atoms(t_moldyn *moldyn,u8 dir,double scale,u8 x,u8 y,u8 z) {
 
        int i;
        t_3dvec *r;
 
+       if(dir==SCALE_UP)
+               scale=1.0+scale;
+
+       if(dir==SCALE_DOWN)
+               scale=1.0-scale;
+
        for(i=0;i<moldyn->count;i++) {
                r=&(moldyn->atom[i].r);
                if(x) r->x*=scale;
@@ -743,68 +1041,55 @@ int scale_atoms(t_moldyn *moldyn,double scale,u8 x,u8 y,u8 z) {
 
 int scale_volume(t_moldyn *moldyn) {
 
-       t_atom *atom;
        t_3dvec *dim,*vdim;
-       double scale,v;
-       t_virial virial;
+       double scale;
        t_linkcell *lc;
-       int i;
 
-       atom=moldyn->atom;
-       dim=&(moldyn->dim);
        vdim=&(moldyn->vis.dim);
+       dim=&(moldyn->dim);
        lc=&(moldyn->lc);
 
-       memset(&virial,0,sizeof(t_virial));
+       /* scaling factor */
+       if(moldyn->pt_scale&P_SCALE_BERENDSEN) {
+               scale=1.0-(moldyn->p_ref-moldyn->p)/moldyn->p_tc;
+               scale=pow(scale,ONE_THIRD);
+       }
+       else {
+               scale=pow(moldyn->p/moldyn->p_ref,ONE_THIRD);
+       }
+moldyn->debug=scale;
+
+       /* scale the atoms and dimensions */
+       scale_atoms(moldyn,SCALE_DIRECT,scale,TRUE,TRUE,TRUE);
+       scale_dim(moldyn,SCALE_DIRECT,scale,TRUE,TRUE,TRUE);
 
-       for(i=0;i<moldyn->count;i++) {
-               virial.xx+=atom[i].virial.xx;
-               virial.yy+=atom[i].virial.yy;
-               virial.zz+=atom[i].virial.zz;
-               virial.xy+=atom[i].virial.xy;
-               virial.xz+=atom[i].virial.xz;
-               virial.yz+=atom[i].virial.yz;
+       /* visualize dimensions */
+       if(vdim->x!=0) {
+               vdim->x=dim->x;
+               vdim->y=dim->y;
+               vdim->z=dim->z;
        }
 
-       /* just a guess so far ... */
-       v=virial.xx+virial.yy+virial.zz;
-
-printf("%f\n",v);
-       /* get pressure from virial */
-       moldyn->p=moldyn->count*K_BOLTZMANN*moldyn->t+ONE_THIRD*v;
-       moldyn->p/=moldyn->volume;
-printf("%f | %f\n",moldyn->p/(ATM),moldyn->p_ref/ATM);
-
-       /* scale factor */
-       if(moldyn->pt_scale&P_SCALE_BERENDSEN)
-               scale=3*sqrt(1-(moldyn->p_ref-moldyn->p)/moldyn->p_tc);
-       else 
-               /* should actually never be used */
-               scale=pow(moldyn->p/moldyn->p_ref,1.0/3.0);
-
-printf("scale = %f\n",scale);
-       /* actual scaling */
-       dim->x*=scale;
-       dim->y*=scale;
-       dim->z*=scale;
-       if(vdim->x) vdim->x=dim->x;
-       if(vdim->y) vdim->y=dim->y;
-       if(vdim->z) vdim->z=dim->z;
-       moldyn->volume*=(scale*scale*scale);
-
-       /* check whether we need a new linkcell init */
-       if((dim->x/moldyn->cutoff!=lc->nx)||
-          (dim->y/moldyn->cutoff!=lc->ny)||
-          (dim->z/moldyn->cutoff!=lc->nx)) {
+       /* recalculate scaled volume */
+       moldyn->volume=dim->x*dim->y*dim->z;
+
+       /* adjust/reinit linkcell */
+       if(((int)(dim->x/moldyn->cutoff)!=lc->nx)||
+          ((int)(dim->y/moldyn->cutoff)!=lc->ny)||
+          ((int)(dim->z/moldyn->cutoff)!=lc->nx)) {
                link_cell_shutdown(moldyn);
-               link_cell_init(moldyn);
+               link_cell_init(moldyn,QUIET);
+       } else {
+               lc->x*=scale;
+               lc->y*=scale;
+               lc->z*=scale;
        }
 
        return 0;
 
 }
 
-double get_e_kin(t_moldyn *moldyn) {
+double e_kin_calc(t_moldyn *moldyn) {
 
        int i;
        t_atom *atom;
@@ -818,11 +1103,6 @@ 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);
@@ -862,7 +1142,7 @@ double estimate_time_step(t_moldyn *moldyn,double nn_dist) {
 
 /* linked list / cell method */
 
-int link_cell_init(t_moldyn *moldyn) {
+int link_cell_init(t_moldyn *moldyn,u8 vol) {
 
        t_linkcell *lc;
        int i;
@@ -883,7 +1163,12 @@ int link_cell_init(t_moldyn *moldyn) {
        if(lc->cells<27)
                printf("[moldyn] FATAL: less then 27 subcells!\n");
 
-       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]));
@@ -918,7 +1203,7 @@ 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]));
        }
 
@@ -1047,32 +1332,42 @@ 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;
 
        /* initialize linked cell method */
-       link_cell_init(moldyn);
+       link_cell_init(moldyn,VERBOSE);
 
        /* logging & visualization */
        e=moldyn->ewrite;
        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;
        moldyn->cutoff_square=moldyn->cutoff*moldyn->cutoff;
 
+       /* energy scaling factor */
+       energy_scale=moldyn->count*EV;
+
        /* calculate initial forces */
        potential_force_calc(moldyn);
+#ifdef DEBUG
+return 0;
+#endif
 
        /* some stupid checks before we actually start calculating bullshit */
        if(moldyn->cutoff>0.5*moldyn->dim.x)
@@ -1087,6 +1382,7 @@ int moldyn_integrate(t_moldyn *moldyn) {
 
        /* zero absolute time */
        moldyn->time=0.0;
+       moldyn->total_steps=0;
 
        /* debugging, ignore */
        moldyn->debug=0;
@@ -1095,7 +1391,8 @@ int moldyn_integrate(t_moldyn *moldyn) {
        printf("[moldyn] integration start, go get a coffee ...\n");
 
        /* executing the schedule */
-       for(sched->count=0;sched->count<sched->total_sched;sched->count++) {
+       sched->count=0;
+       while(sched->count<sched->total_sched) {
 
                /* setting amount of runs and finite time step size */
                moldyn->tau=sched->tau[sched->count];
@@ -1109,29 +1406,50 @@ int moldyn_integrate(t_moldyn *moldyn) {
                /* integration step */
                moldyn->integrate(moldyn);
 
+               /* calculate kinetic energy, temperature and pressure */
+               e_kin_calc(moldyn);
+               temperature_calc(moldyn);
+               virial_sum(moldyn);
+               pressure_calc(moldyn);
+               average_and_fluctuation_calc(moldyn);
+
                /* p/t scaling */
                if(moldyn->pt_scale&(T_SCALE_BERENDSEN|T_SCALE_DIRECT))
                        scale_velocity(moldyn,FALSE);
                if(moldyn->pt_scale&(P_SCALE_BERENDSEN|P_SCALE_DIRECT))
                        scale_volume(moldyn);
 
-printf("-> %f\n",thermodynamic_pressure_calc(moldyn)/ATM);
-
                /* check for log & visualization */
                if(e) {
                        if(!(i%e))
-                               update_e_kin(moldyn);
                                dprintf(moldyn->efd,
                                        "%f %f %f %f\n",
-                                       moldyn->time,moldyn->ekin,
-                                       moldyn->energy,
-                                       get_total_energy(moldyn));
+                                       moldyn->time,moldyn->ekin/energy_scale,
+                                       moldyn->energy/energy_scale,
+                                       get_total_energy(moldyn)/energy_scale);
                }
                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->p_avg/BAR,
+                                        moldyn->gp/BAR,moldyn->gp_avg/BAR);
+                       }
+               }
+               if(t) {
+                       if(!(i%t)) {
+                               dprintf(moldyn->tfd,
+                                       "%f %f %f\n",
+                                       moldyn->time,moldyn->t,moldyn->t_avg);
                        }
                }
                if(s) {
@@ -1152,23 +1470,35 @@ printf("-> %f\n",thermodynamic_pressure_calc(moldyn)/ATM);
                        if(!(i%v)) {
                                visual_atoms(&(moldyn->vis),moldyn->time,
                                             moldyn->atom,moldyn->count);
-                               printf("\rsched: %d, steps: %d, debug: %d",
-                                      sched->count,i,moldyn->debug);
-                               fflush(stdout);
                        }
                }
 
+               /* display progress */
+               if(!(i%10)) {
+       printf("\rsched:%d, steps:%d, T:%3.1f/%3.1f P:%4.1f/%4.1f V:%6.1f",
+              sched->count,i,
+              moldyn->t,moldyn->t_avg,
+              moldyn->p_avg/BAR,moldyn->p/BAR,
+              moldyn->volume);
+       fflush(stdout);
+               }
+
                /* increase absolute time */
                moldyn->time+=moldyn->tau;
+               moldyn->total_steps+=1;
 
        }
 
                /* check for hooks */
-               if(sched->hook)
+               if(sched->hook) {
+                       printf("\n ## schedule hook %d/%d start ##\n",
+                              sched->count+1,sched->total_sched-1);
                        sched->hook(moldyn,sched->hook_params);
+                       printf(" ## schedule hook end ##\n");
+               }
 
-               /* get a new info line */
-               printf("\n");
+               /* increase the schedule counter */
+               sched->count+=1;
 
        }
 
@@ -1246,8 +1576,8 @@ int potential_force_calc(t_moldyn *moldyn) {
        /* reset energy */
        moldyn->energy=0.0;
 
-       /* reset virial */
-       moldyn->vt1=0.0;
+       /* reset global virial */
+       memset(&(moldyn->gvir),0,sizeof(t_virial));
 
        /* reset force, site energy and virial of every atom */
        for(i=0;i<count;i++) {
@@ -1269,12 +1599,15 @@ 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 */
                if(itom[i].attr&ATOM_ATTR_1BP)
-                       moldyn->func1b(moldyn,&(itom[i]));
+                       if(moldyn->func1b)
+                               moldyn->func1b(moldyn,&(itom[i]));
 
                if(!(itom[i].attr&(ATOM_ATTR_2BP|ATOM_ATTR_3BP)))
                        continue;
@@ -1289,6 +1622,45 @@ 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]);
@@ -1305,25 +1677,70 @@ 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) {
 
-                               /* copy the neighbour lists */
-                               memcpy(neighbour_i2,neighbour_i,
-                                      27*sizeof(t_list));
+                               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);
+
+                               }
+
+                               }
+
+                               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]);
@@ -1347,39 +1764,52 @@ 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");
+       //printf("\n\n");
 #endif
 #ifdef VDEBUG
-printf("\n\n");
+       printf("\n\n");
+#endif
+
+       }
+
+#ifdef DEBUG
+       printf("\nATOM 0: %f %f %f\n\n",itom->f.x,itom->f.y,itom->f.z);
 #endif
 
-temperature_calc(moldyn);
-pressure_calc(moldyn);
-ideal_gas_law_pressure(moldyn);
+       /* calculate global virial */
+       for(i=0;i<count;i++) {
+               moldyn->gvir.xx+=moldyn->atom[i].r.x*moldyn->atom[i].f.x;
+               moldyn->gvir.yy+=moldyn->atom[i].r.y*moldyn->atom[i].f.y;
+               moldyn->gvir.zz+=moldyn->atom[i].r.z*moldyn->atom[i].f.z;
+               moldyn->gvir.xy+=moldyn->atom[i].r.y*moldyn->atom[i].f.x;
+               moldyn->gvir.xz+=moldyn->atom[i].r.z*moldyn->atom[i].f.x;
+               moldyn->gvir.yz+=moldyn->atom[i].r.z*moldyn->atom[i].f.y;
+       }
 
        return 0;
 }
@@ -1388,23 +1818,25 @@ ideal_gas_law_pressure(moldyn);
  * 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;
-       a->virial.zz-=f->z*d->z;
-       a->virial.xy-=f->x*d->y;
-       a->virial.xz-=f->x*d->z;
-       a->virial.yz-=f->y*d->z;
+       a->virial.xx+=f->x*d->x;
+       a->virial.yy+=f->y*d->y;
+       a->virial.zz+=f->z*d->z;
+       a->virial.xy+=f->x*d->y;
+       a->virial.xz+=f->x*d->z;
+       a->virial.yz+=f->y*d->z;
 
        return 0;
 }
 
 /*
- * periodic boundayr checking
+ * periodic boundary 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;
@@ -1431,779 +1863,6 @@ 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;
-}
-
-/* lennard jones potential & force for one sort of atoms */
-int lennard_jones(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
-
-       t_lj_params *params;
-       t_3dvec force,distance;
-       double d,h1,h2;
-       double eps,sig6,sig12;
-
-       params=moldyn->pot2b_params;
-       eps=params->epsilon4;
-       sig6=params->sigma6;
-       sig12=params->sigma12;
-
-       if(ai<aj) return 0;
-
-       v3_sub(&distance,&(aj->r),&(ai->r));
-       if(bc) check_per_bound(moldyn,&distance);
-       d=v3_absolute_square(&distance);        /* 1/r^2 */
-       if(d<=moldyn->cutoff_square) {
-               d=1.0/d;                        /* 1/r^2 */
-               h2=d*d;                         /* 1/r^4 */
-               h2*=d;                          /* 1/r^6 */
-               h1=h2*h2;                       /* 1/r^12 */
-               moldyn->energy+=(eps*(sig12*h1-sig6*h2)-params->uc);
-               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(&(aj->f),&(aj->f),&force);
-               v3_scale(&force,&distance,-1.0*d); /* f = - grad E */
-               v3_add(&(ai->f),&(ai->f),&force);
-               virial_calc(ai,&force,&distance);
-               virial_calc(aj,&force,&distance); /* f and d signe switched */
-               moldyn->vt1-=v3_scalar_product(&force,&distance);
-       }
-
-       return 0;
-}
-
-/*
- * tersoff potential & force for 2 sorts of atoms
- */
-
-/* create mixed terms from parameters and set them */
-int tersoff_mult_complete_params(t_tersoff_mult_params *p) {
-
-       printf("[moldyn] tersoff parameter completion\n");
-       p->S2[0]=p->S[0]*p->S[0];
-       p->S2[1]=p->S[1]*p->S[1];
-       p->Smixed=sqrt(p->S[0]*p->S[1]);
-       p->S2mixed=p->Smixed*p->Smixed;
-       p->Rmixed=sqrt(p->R[0]*p->R[1]);
-       p->Amixed=sqrt(p->A[0]*p->A[1]);
-       p->Bmixed=sqrt(p->B[0]*p->B[1]);
-       p->lambda_m=0.5*(p->lambda[0]+p->lambda[1]);
-       p->mu_m=0.5*(p->mu[0]+p->mu[1]);
-
-       printf("[moldyn] tersoff mult parameter info:\n");
-       printf("  S (A)  | %f | %f | %f\n",p->S[0],p->S[1],p->Smixed);
-       printf("  R (A)  | %f | %f | %f\n",p->R[0],p->R[1],p->Rmixed);
-       printf("  A (eV) | %f | %f | %f\n",p->A[0]/EV,p->A[1]/EV,p->Amixed/EV);
-       printf("  B (eV) | %f | %f | %f\n",p->B[0]/EV,p->B[1]/EV,p->Bmixed/EV);
-       printf("  lambda | %f | %f | %f\n",p->lambda[0],p->lambda[1],
-                                         p->lambda_m);
-       printf("  mu     | %f | %f | %f\n",p->mu[0],p->mu[1],p->mu_m);
-       printf("  beta   | %.10f | %.10f\n",p->beta[0],p->beta[1]);
-       printf("  n      | %f | %f\n",p->n[0],p->n[1]);
-       printf("  c      | %f | %f\n",p->c[0],p->c[1]);
-       printf("  d      | %f | %f\n",p->d[0],p->d[1]);
-       printf("  h      | %f | %f\n",p->h[0],p->h[1]);
-       printf("  chi    | %f \n",p->chi);
-
-       return 0;
-}
-
-/* tersoff 1 body part */
-int tersoff_mult_1bp(t_moldyn *moldyn,t_atom *ai) {
-
-       int brand;
-       t_tersoff_mult_params *params;
-       t_tersoff_exchange *exchange;
-       
-       brand=ai->brand;
-       params=moldyn->pot1b_params;
-       exchange=&(params->exchange);
-
-       /*
-        * simple: point constant parameters only depending on atom i to
-        *         their right values
-        */
-
-       exchange->beta_i=&(params->beta[brand]);
-       exchange->n_i=&(params->n[brand]);
-       exchange->c_i=&(params->c[brand]);
-       exchange->d_i=&(params->d[brand]);
-       exchange->h_i=&(params->h[brand]);
-
-       exchange->betaini=pow(*(exchange->beta_i),*(exchange->n_i));
-       exchange->ci2=params->c[brand]*params->c[brand];
-       exchange->di2=params->d[brand]*params->d[brand];
-       exchange->ci2di2=exchange->ci2/exchange->di2;
-
-       return 0;
-}
-       
-/* tersoff 2 body part */
-int tersoff_mult_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
-
-       t_tersoff_mult_params *params;
-       t_tersoff_exchange *exchange;
-       t_3dvec dist_ij,force;
-       double d_ij,d_ij2;
-       double A,B,R,S,S2,lambda,mu;
-       double f_r,df_r;
-       double f_c,df_c;
-       int brand;
-       double s_r;
-       double arg;
-
-       params=moldyn->pot2b_params;
-       brand=aj->brand;
-       exchange=&(params->exchange);
-
-       /* clear 3bp and 2bp post run */
-       exchange->run3bp=0;
-       exchange->run2bp_post=0;
-
-       /* reset S > r > R mark */
-       exchange->d_ij_between_rs=0;
-       
-       /*
-        * calc of 2bp contribution of V_ij and dV_ij/ji
-        *
-        * for Vij and dV_ij we need:
-        * - f_c_ij, df_c_ij
-        * - f_r_ij, df_r_ij
-        *
-        * for dV_ji we need:
-        * - f_c_ji = f_c_ij, df_c_ji = df_c_ij
-        * - f_r_ji = f_r_ij; df_r_ji = df_r_ij
-        *
-        */
-
-       /* constants */
-       if(brand==ai->brand) {
-               S=params->S[brand];
-               S2=params->S2[brand];
-               R=params->R[brand];
-               A=params->A[brand];
-               B=params->B[brand];
-               lambda=params->lambda[brand];
-               mu=params->mu[brand];
-               exchange->chi=1.0;
-       }
-       else {
-               S=params->Smixed;
-               S2=params->S2mixed;
-               R=params->Rmixed;
-               A=params->Amixed;
-               B=params->Bmixed;
-               lambda=params->lambda_m;
-               mu=params->mu_m;
-               params->exchange.chi=params->chi;
-       }
-
-       /* dist_ij, d_ij */
-       v3_sub(&dist_ij,&(aj->r),&(ai->r));
-       if(bc) check_per_bound(moldyn,&dist_ij);
-       d_ij2=v3_absolute_square(&dist_ij);
-
-       /* if d_ij2 > S2 => no force & potential energy contribution */
-       if(d_ij2>S2)
-               return 0;
-
-       /* now we will need the distance */
-       //d_ij=v3_norm(&dist_ij);
-       d_ij=sqrt(d_ij2);
-
-       /* save for use in 3bp */
-       exchange->d_ij=d_ij;
-       exchange->d_ij2=d_ij2;
-       exchange->dist_ij=dist_ij;
-
-       /* more constants */
-       exchange->beta_j=&(params->beta[brand]);
-       exchange->n_j=&(params->n[brand]);
-       exchange->c_j=&(params->c[brand]);
-       exchange->d_j=&(params->d[brand]);
-       exchange->h_j=&(params->h[brand]);
-       if(brand==ai->brand) {
-               exchange->betajnj=exchange->betaini;
-               exchange->cj2=exchange->ci2;
-               exchange->dj2=exchange->di2;
-               exchange->cj2dj2=exchange->ci2di2;
-       }
-       else {
-               exchange->betajnj=pow(*(exchange->beta_j),*(exchange->n_j));
-               exchange->cj2=params->c[brand]*params->c[brand];
-               exchange->dj2=params->d[brand]*params->d[brand];
-               exchange->cj2dj2=exchange->cj2/exchange->dj2;
-       }
-
-       /* f_r_ij = f_r_ji, df_r_ij = df_r_ji */
-       f_r=A*exp(-lambda*d_ij);
-       df_r=lambda*f_r/d_ij;
-
-       /* f_a, df_a calc (again, same for ij and ji) | save for later use! */
-       exchange->f_a=-B*exp(-mu*d_ij);
-       exchange->df_a=mu*exchange->f_a/d_ij;
-
-       /* f_c, df_c calc (again, same for ij and ji) */
-       if(d_ij<R) {
-               /* f_c = 1, df_c = 0 */
-               f_c=1.0;
-               df_c=0.0;
-               /* two body contribution (ij, ji) */
-               v3_scale(&force,&dist_ij,-df_r);
-       }
-       else {
-               s_r=S-R;
-               arg=M_PI*(d_ij-R)/s_r;
-               f_c=0.5+0.5*cos(arg);
-               df_c=0.5*sin(arg)*(M_PI/(s_r*d_ij));
-               /* two body contribution (ij, ji) */
-               v3_scale(&force,&dist_ij,-df_c*f_r-df_r*f_c);
-               /* tell 3bp that S > r > R */
-               exchange->d_ij_between_rs=1;
-       }
-
-       /* add forces of 2bp (ij, ji) contribution
-        * dVij = dVji and we sum up both: no 1/2) */
-       v3_add(&(ai->f),&(ai->f),&force);
-
-       /* virial */
-       ai->virial.xx-=force.x*dist_ij.x;
-       ai->virial.yy-=force.y*dist_ij.y;
-       ai->virial.zz-=force.z*dist_ij.z;
-       ai->virial.xy-=force.x*dist_ij.y;
-       ai->virial.xz-=force.x*dist_ij.z;
-       ai->virial.yz-=force.y*dist_ij.z;
-
-#ifdef DEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVij, dVji (2bp) contrib:\n");
-       printf("%f | %f\n",force.x,ai->f.x);
-       printf("%f | %f\n",force.y,ai->f.y);
-       printf("%f | %f\n",force.z,ai->f.z);
-}
-#endif
-#ifdef VDEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVij, dVji (2bp) contrib:\n");
-       printf("%f | %f\n",force.x*dist_ij.x,ai->virial.xx);
-       printf("%f | %f\n",force.y*dist_ij.y,ai->virial.yy);
-       printf("%f | %f\n",force.z*dist_ij.z,ai->virial.zz);
-}
-#endif
-
-       /* energy 2bp contribution (ij, ji) is 0.5 f_r f_c ... */
-       moldyn->energy+=(0.5*f_r*f_c);
-
-       /* save for use in 3bp */
-       exchange->f_c=f_c;
-       exchange->df_c=df_c;
-
-       /* enable the run of 3bp function and 2bp post processing */
-       exchange->run3bp=1;
-       exchange->run2bp_post=1;
-
-       /* reset 3bp sums */
-       exchange->zeta_ij=0.0;
-       exchange->zeta_ji=0.0;
-       v3_zero(&(exchange->dzeta_ij));
-       v3_zero(&(exchange->dzeta_ji));
-
-       return 0;
-}
-
-/* tersoff 2 body post part */
-
-int tersoff_mult_post_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
-
-       /*
-        * here we have to allow for the 3bp sums
-        *
-        * that is:
-        * - zeta_ij, dzeta_ij
-        * - zeta_ji, dzeta_ji
-        *
-        * to compute the 3bp contribution to:
-        * - Vij, dVij
-        * - dVji
-        *
-        */
-
-       t_tersoff_mult_params *params;
-       t_tersoff_exchange *exchange;
-
-       t_3dvec force,temp;
-       t_3dvec *dist_ij;
-       double b,db,tmp;
-       double f_c,df_c,f_a,df_a;
-       double chi,ni,betaini,nj,betajnj;
-       double zeta;
-
-       params=moldyn->pot2b_params;
-       exchange=&(params->exchange);
-
-       /* we do not run if f_c_ij was detected to be 0! */
-       if(!(exchange->run2bp_post))
-               return 0;
-
-       f_c=exchange->f_c;
-       df_c=exchange->df_c;
-       f_a=exchange->f_a;
-       df_a=exchange->df_a;
-       betaini=exchange->betaini;
-       betajnj=exchange->betajnj;
-       ni=*(exchange->n_i);
-       nj=*(exchange->n_j);
-       chi=exchange->chi;
-       dist_ij=&(exchange->dist_ij);
-       
-       /* Vij and dVij */
-       zeta=exchange->zeta_ij;
-       if(zeta==0.0) {
-               moldyn->debug++;                /* just for debugging ... */
-               b=chi;
-               v3_scale(&force,dist_ij,df_a*b*f_c);
-       }
-       else {
-               tmp=betaini*pow(zeta,ni-1.0);           /* beta^n * zeta^n-1 */
-               b=(1+zeta*tmp);                         /* 1 + beta^n zeta^n */
-               db=chi*pow(b,-1.0/(2*ni)-1);            /* x(...)^(-1/2n - 1) */
-               b=db*b;                                 /* b_ij */
-               db*=-0.5*tmp;                           /* db_ij */
-               v3_scale(&force,&(exchange->dzeta_ij),f_a*db);
-               v3_scale(&temp,dist_ij,df_a*b);
-               v3_add(&force,&force,&temp);
-               v3_scale(&force,&force,f_c);
-       }
-       v3_scale(&temp,dist_ij,df_c*b*f_a);
-       v3_add(&force,&force,&temp);
-       v3_scale(&force,&force,-0.5);
-
-       /* add force */
-       v3_add(&(ai->f),&(ai->f),&force);
-
-       /* virial */
-       ai->virial.xx-=force.x*dist_ij->x;
-       ai->virial.yy-=force.y*dist_ij->y;
-       ai->virial.zz-=force.z*dist_ij->z;
-       ai->virial.xy-=force.x*dist_ij->y;
-       ai->virial.xz-=force.x*dist_ij->z;
-       ai->virial.yz-=force.y*dist_ij->z;
-
-#ifdef DEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVij (3bp) contrib:\n");
-       printf("%f | %f\n",force.x,ai->f.x);
-       printf("%f | %f\n",force.y,ai->f.y);
-       printf("%f | %f\n",force.z,ai->f.z);
-}
-#endif
-#ifdef VDEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVij (3bp) contrib:\n");
-       printf("%f | %f\n",force.x*dist_ij->x,ai->virial.xx);
-       printf("%f | %f\n",force.y*dist_ij->y,ai->virial.yy);
-       printf("%f | %f\n",force.z*dist_ij->z,ai->virial.zz);
-}
-#endif
-
-       /* add energy of 3bp sum */
-       moldyn->energy+=(0.5*f_c*b*f_a);
-
-       /* dVji */
-       zeta=exchange->zeta_ji;
-       if(zeta==0.0) {
-               moldyn->debug++;
-               b=chi;
-               v3_scale(&force,dist_ij,df_a*b*f_c);
-       }
-       else {
-               tmp=betajnj*pow(zeta,nj-1.0);           /* beta^n * zeta^n-1 */
-               b=(1+zeta*tmp);                         /* 1 + beta^n zeta^n */
-               db=chi*pow(b,-1.0/(2*nj)-1);            /* x(...)^(-1/2n - 1) */
-               b=db*b;                                 /* b_ij */
-               db*=-0.5*tmp;                           /* db_ij */
-               v3_scale(&force,&(exchange->dzeta_ji),f_a*db);
-               v3_scale(&temp,dist_ij,df_a*b);
-               v3_add(&force,&force,&temp);
-               v3_scale(&force,&force,f_c);
-       }
-       v3_scale(&temp,dist_ij,df_c*b*f_a);
-       v3_add(&force,&force,&temp);
-       v3_scale(&force,&force,-0.5);
-
-       /* add force */
-       v3_add(&(ai->f),&(ai->f),&force);
-
-       /* virial - plus sign, as dist_ij = - dist_ji - (really??) */
-// TEST ... with a minus instead
-       ai->virial.xx-=force.x*dist_ij->x;
-       ai->virial.yy-=force.y*dist_ij->y;
-       ai->virial.zz-=force.z*dist_ij->z;
-       ai->virial.xy-=force.x*dist_ij->y;
-       ai->virial.xz-=force.x*dist_ij->z;
-       ai->virial.yz-=force.y*dist_ij->z;
-
-#ifdef DEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVji (3bp) contrib:\n");
-       printf("%f | %f\n",force.x,ai->f.x);
-       printf("%f | %f\n",force.y,ai->f.y);
-       printf("%f | %f\n",force.z,ai->f.z);
-}
-#endif
-#ifdef VDEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVji (3bp) contrib:\n");
-       printf("%f | %f\n",force.x*dist_ij->x,ai->virial.xx);
-       printf("%f | %f\n",force.y*dist_ij->y,ai->virial.yy);
-       printf("%f | %f\n",force.z*dist_ij->z,ai->virial.zz);
-}
-#endif
-
-       return 0;
-}
-
-/* tersoff 3 body part */
-
-int tersoff_mult_3bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,t_atom *ak,u8 bc) {
-
-       t_tersoff_mult_params *params;
-       t_tersoff_exchange *exchange;
-       t_3dvec dist_ij,dist_ik,dist_jk;
-       t_3dvec temp1,temp2;
-       t_3dvec *dzeta;
-       double R,S,S2,s_r;
-       double B,mu;
-       double d_ij,d_ik,d_jk,d_ij2,d_ik2,d_jk2;
-       double rr,dd;
-       double f_c,df_c;
-       double f_c_ik,df_c_ik,arg;
-       double f_c_jk;
-       double n,c,d,h;
-       double c2,d2,c2d2;
-       double cos_theta,d_costheta1,d_costheta2;
-       double h_cos,d2_h_cos2;
-       double frac,g,zeta,chi;
-       double tmp;
-       int brand;
-
-       params=moldyn->pot3b_params;
-       exchange=&(params->exchange);
-
-       if(!(exchange->run3bp))
-               return 0;
-
-       /*
-        * calc of 3bp contribution of V_ij and dV_ij/ji/jk &
-        * 2bp contribution of dV_jk
-        *
-        * for Vij and dV_ij we still need:
-        * - b_ij, db_ij (zeta_ij)
-        *   - f_c_ik, df_c_ik, constants_i, cos_theta_ijk, d_costheta_ijk
-        *
-        * for dV_ji we still need:
-        * - b_ji, db_ji (zeta_ji)
-        *   - f_c_jk, d_c_jk, constants_j, cos_theta_jik, d_costheta_jik
-        *
-        * for dV_jk we need:
-        * - f_c_jk
-        * - f_a_jk
-        * - db_jk (zeta_jk)
-        *   - f_c_ji, df_c_ji, constants_j, cos_theta_jki, d_costheta_jki
-        *
-        */
-
-       /*
-        * get exchange data 
-        */
-
-       /* dist_ij, d_ij - this is < S_ij ! */
-       dist_ij=exchange->dist_ij;
-       d_ij=exchange->d_ij;
-       d_ij2=exchange->d_ij2;
-
-       /* f_c_ij, df_c_ij (same for ji) */
-       f_c=exchange->f_c;
-       df_c=exchange->df_c;
-
-       /*
-        * calculate unknown values now ...
-        */
-
-       /* V_ij and dV_ij stuff (in b_ij there is f_c_ik) */
-
-       /* dist_ik, d_ik */
-       v3_sub(&dist_ik,&(ak->r),&(ai->r));
-       if(bc) check_per_bound(moldyn,&dist_ik);
-       d_ik2=v3_absolute_square(&dist_ik);
-
-       /* ik constants */
-       brand=ai->brand;
-       if(brand==ak->brand) {
-               R=params->R[brand];
-               S=params->S[brand];
-               S2=params->S2[brand];
-       }
-       else {
-               R=params->Rmixed;
-               S=params->Smixed;
-               S2=params->S2mixed;
-       }
-
-       /* zeta_ij/dzeta_ij contribution only for d_ik < S */
-       if(d_ik2<S2) {
-
-               /* now we need d_ik */
-               d_ik=sqrt(d_ik2);
-
-               /* get constants_i from exchange data */
-               n=*(exchange->n_i);
-               c=*(exchange->c_i);
-               d=*(exchange->d_i);
-               h=*(exchange->h_i);
-               c2=exchange->ci2;
-               d2=exchange->di2;
-               c2d2=exchange->ci2di2;
-
-               /* cosine of theta_ijk by scalaproduct */
-               rr=v3_scalar_product(&dist_ij,&dist_ik);
-               dd=d_ij*d_ik;
-               cos_theta=rr/dd;
-
-               /* d_costheta */
-               tmp=1.0/dd;
-               d_costheta1=cos_theta/d_ij2-tmp;
-               d_costheta2=cos_theta/d_ik2-tmp;
-
-               /* some usefull values */
-               h_cos=(h-cos_theta);
-               d2_h_cos2=d2+(h_cos*h_cos);
-               frac=c2/(d2_h_cos2);
-
-               /* g(cos_theta) */
-               g=1.0+c2d2-frac;
-
-               /* d_costheta_ij and dg(cos_theta) - needed in any case! */
-               v3_scale(&temp1,&dist_ij,d_costheta1);
-               v3_scale(&temp2,&dist_ik,d_costheta2);
-               v3_add(&temp1,&temp1,&temp2);
-               v3_scale(&temp1,&temp1,-2.0*frac*h_cos/d2_h_cos2); /* dg */
-
-               /* f_c_ik & df_c_ik + {d,}zeta contribution */
-               dzeta=&(exchange->dzeta_ij);
-               if(d_ik<R) {
-                       /* {d,}f_c_ik */
-                       // => f_c_ik=1.0;
-                       // => df_c_ik=0.0; of course we do not set this!
-
-                       /* zeta_ij */
-                       exchange->zeta_ij+=g;
-
-                       /* dzeta_ij */
-                       v3_add(dzeta,dzeta,&temp1);
-               }
-               else {
-                       /* {d,}f_c_ik */
-                       s_r=S-R;
-                       arg=M_PI*(d_ik-R)/s_r;
-                       f_c_ik=0.5+0.5*cos(arg);
-                       df_c_ik=0.5*sin(arg)*(M_PI/(s_r*d_ik));
-
-                       /* zeta_ij */
-                       exchange->zeta_ij+=f_c_ik*g;
-
-                       /* dzeta_ij */
-                       v3_scale(&temp1,&temp1,f_c_ik);
-                       v3_scale(&temp2,&dist_ik,g*df_c_ik);
-                       v3_add(&temp1,&temp1,&temp2);
-                       v3_add(dzeta,dzeta,&temp1);
-               }
-       }
-
-       /* dV_ji stuff (in b_ji there is f_c_jk) + dV_jk stuff! */
-
-       /* dist_jk, d_jk */
-       v3_sub(&dist_jk,&(ak->r),&(aj->r));
-       if(bc) check_per_bound(moldyn,&dist_jk);
-       d_jk2=v3_absolute_square(&dist_jk);
-
-       /* jk constants */
-       brand=aj->brand;
-       if(brand==ak->brand) {
-               R=params->R[brand];
-               S=params->S[brand];
-               S2=params->S2[brand];
-               B=params->B[brand];
-               mu=params->mu[brand];
-               chi=1.0;
-       }
-       else {
-               R=params->Rmixed;
-               S=params->Smixed;
-               S2=params->S2mixed;
-               B=params->Bmixed;
-               mu=params->mu_m;
-               chi=params->chi;
-       }
-
-       /* zeta_ji/dzeta_ji contribution only for d_jk < S_jk */
-       if(d_jk2<S2) {
-
-               /* now we need d_ik */
-               d_jk=sqrt(d_jk2);
-
-               /* constants_j from exchange data */
-               n=*(exchange->n_j);
-               c=*(exchange->c_j);
-               d=*(exchange->d_j);
-               h=*(exchange->h_j);
-               c2=exchange->cj2;
-               d2=exchange->dj2;
-               c2d2=exchange->cj2dj2;
-
-               /* cosine of theta_jik by scalaproduct */
-               rr=-v3_scalar_product(&dist_ij,&dist_jk); /* -1, as ij -> ji */
-               dd=d_ij*d_jk;
-               cos_theta=rr/dd;
-
-               /* d_costheta */
-               d_costheta1=1.0/dd;
-               d_costheta2=cos_theta/d_ij2;
-
-               /* some usefull values */
-               h_cos=(h-cos_theta);
-               d2_h_cos2=d2+(h_cos*h_cos);
-               frac=c2/(d2_h_cos2);
-
-               /* g(cos_theta) */
-               g=1.0+c2d2-frac;
-
-               /* d_costheta_jik and dg(cos_theta) - needed in any case! */
-               v3_scale(&temp1,&dist_jk,d_costheta1);
-               v3_scale(&temp2,&dist_ij,-d_costheta2); /* ji -> ij => -1 */
-               //v3_add(&temp1,&temp1,&temp2);
-               v3_sub(&temp1,&temp1,&temp2); /* there is a minus! */
-               v3_scale(&temp1,&temp1,-2.0*frac*h_cos/d2_h_cos2); /* dg */
-
-               /* store dg in temp2 and use it for dVjk later */
-               v3_copy(&temp2,&temp1);
-
-               /* f_c_jk + {d,}zeta contribution (df_c_jk = 0) */
-               dzeta=&(exchange->dzeta_ji);
-               if(d_jk<R) {
-                       /* f_c_jk */
-                       f_c_jk=1.0;
-
-                       /* zeta_ji */
-                       exchange->zeta_ji+=g;
-
-                       /* dzeta_ji */
-                       v3_add(dzeta,dzeta,&temp1);
-               }
-               else {
-                       /* f_c_jk */
-                       s_r=S-R;
-                       arg=M_PI*(d_jk-R)/s_r;
-                       f_c_jk=0.5+0.5*cos(arg);
-
-                       /* zeta_ji */
-                       exchange->zeta_ji+=f_c_jk*g;
-
-                       /* dzeta_ji */
-                       v3_scale(&temp1,&temp1,f_c_jk);
-                       v3_add(dzeta,dzeta,&temp1);
-               }
-
-               /* dV_jk stuff | add force contribution on atom i immediately */
-               if(exchange->d_ij_between_rs) {
-                       zeta=f_c*g;
-                       v3_scale(&temp1,&temp2,f_c);
-                       v3_scale(&temp2,&dist_ij,df_c*g);
-                       v3_add(&temp2,&temp2,&temp1); /* -> dzeta_jk in temp2 */
-               }
-               else {
-                       zeta=g;
-                       // dzeta_jk is simply dg, which is stored in temp2
-               }
-               /* betajnj * zeta_jk ^ nj-1 */
-               tmp=exchange->betajnj*pow(zeta,(n-1.0));
-               tmp=-chi/2.0*pow((1+tmp*zeta),(-1.0/(2.0*n)-1))*tmp;
-               v3_scale(&temp2,&temp2,tmp*B*exp(-mu*d_jk)*f_c_jk*0.5);
-               v3_add(&(ai->f),&(ai->f),&temp2); /* -1 skipped in f_a calc ^ */
-                                                 /* scaled with 0.5 ^ */
-
-               /* virial */
-               ai->virial.xx-=temp2.x*dist_jk.x;
-               ai->virial.yy-=temp2.y*dist_jk.y;
-               ai->virial.zz-=temp2.z*dist_jk.z;
-               ai->virial.xy-=temp2.x*dist_jk.y;
-               ai->virial.xz-=temp2.x*dist_jk.z;
-               ai->virial.yz-=temp2.y*dist_jk.z;
-
-#ifdef DEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVjk (3bp) contrib:\n");
-       printf("%f | %f\n",temp2.x,ai->f.x);
-       printf("%f | %f\n",temp2.y,ai->f.y);
-       printf("%f | %f\n",temp2.z,ai->f.z);
-}
-#endif
-#ifdef VDEBUG
-if(ai==&(moldyn->atom[0])) {
-       printf("dVjk (3bp) contrib:\n");
-       printf("%f | %f\n",temp2.x*dist_jk.x,ai->virial.xx);
-       printf("%f | %f\n",temp2.y*dist_jk.y,ai->virial.yy);
-       printf("%f | %f\n",temp2.z*dist_jk.z,ai->virial.zz);
-}
-#endif
-
-       }
-
-       return 0;
-}
-
-
 /*
  * debugging / critical check functions
  */
@@ -2255,3 +1914,26 @@ int moldyn_bc_check(t_moldyn *moldyn) {
 
        return 0;
 }
+
+/*
+ * post processing functions
+ */
+
+int get_line(int fd,char *line,int max) {
+
+       int count,ret;
+
+       count=0;
+
+       while(1) {
+               if(count==max) return count;
+               ret=read(fd,line+count,1);
+               if(ret<=0) return ret;
+               if(line[count]=='\n') {
+                       line[count]='\0';
+                       return count+1;
+               }
+               count+=1;
+       }
+}
+