+ t_pcc pcc;
+ double norm;
+ int i;
+
+ pcc.dr=dr;
+ pcc.o1=moldyn->cutoff/dr;
+ pcc.o2=2*pcc.o1;
+
+ if(pcc.o1*dr<=moldyn->cutoff)
+ printf("[moldyn] WARNING: pcc (low #slots)\n");
+
+ printf("[moldyn] pair correlation calc info:\n");
+ printf(" time: %f\n",moldyn->time);
+ printf(" count: %d\n",moldyn->count);
+ printf(" cutoff: %f\n",moldyn->cutoff);
+ printf(" temperature: cur=%f avg=%f\n",moldyn->t,moldyn->t_avg);
+
+ if(ptr!=NULL) {
+ pcc.stat=(double *)ptr;
+ }
+ else {
+ pcc.stat=(double *)malloc(3*pcc.o1*sizeof(double));
+ if(pcc.stat==NULL) {
+ perror("[moldyn] pair correlation malloc");
+ return -1;
+ }
+ }
+
+ memset(pcc.stat,0,3*pcc.o1*sizeof(double));
+
+ /* process */
+ process_2b_bonds(moldyn,&pcc,calculate_pair_correlation_process);
+
+ /* normalization */
+ for(i=1;i<pcc.o1;i++) {
+ // normalization: 4 pi r^2 dr
+ // here: not double counting pairs -> 2 pi r r dr
+ // ... and actually it's a constant times r^2
+ norm=i*i*dr*dr;
+ pcc.stat[i]/=norm;
+ pcc.stat[pcc.o1+i]/=norm;
+ pcc.stat[pcc.o2+i]/=norm;
+ }
+ /* */
+
+ if(ptr==NULL) {
+ /* todo: store/print pair correlation function */
+ free(pcc.stat);
+ }
+
+ return 0;
+}
+
+int bond_analyze_process(t_moldyn *moldyn,t_atom *itom,t_atom *jtom,
+ void *data,u8 bc) {
+
+ t_ba *ba;
+ t_3dvec dist;
+ double d;
+
+ if(itom->tag>=jtom->tag)
+ return 0;
+
+ /* distance */
+ v3_sub(&dist,&(jtom->r),&(itom->r));
+ if(bc) check_per_bound(moldyn,&dist);
+ d=v3_absolute_square(&dist);
+
+ /* ignore if greater or equal cutoff */
+ if(d>moldyn->cutoff_square)
+ return 0;
+
+ /* check for potential bond */
+ if(moldyn->check_2b_bond(moldyn,itom,jtom,bc)==FALSE)
+ return 0;
+
+ /* now count this bonding ... */
+ ba=data;
+
+ /* increase total bond counter
+ * ... double counting!
+ */
+ ba->tcnt+=2;
+
+ if(itom->brand==0)
+ ba->acnt[jtom->tag]+=1;
+ else
+ ba->bcnt[jtom->tag]+=1;