+/*
+ * function to find/callback all combinations of 2 body bonds
+ */
+
+int process_2b_bonds(t_moldyn *moldyn,void *data,
+ int (*process)(t_moldyn *moldyn,t_atom *itom,t_atom *jtom,
+ void *data,u8 bc)) {
+
+ t_linkcell *lc;
+#ifdef STATIC_LISTS
+ int *neighbour[27];
+ int p;
+#else
+ t_list neighbour[27];
+#endif
+ u8 bc;
+ t_atom *itom,*jtom;
+ int i,j;
+ t_list *this;
+
+ lc=&(moldyn->lc);
+
+ link_cell_init(moldyn,VERBOSE);
+
+ itom=moldyn->atom;
+
+ for(i=0;i<moldyn->count;i++) {
+ /* neighbour indexing */
+ link_cell_neighbour_index(moldyn,
+ (itom[i].r.x+moldyn->dim.x/2)/lc->x,
+ (itom[i].r.y+moldyn->dim.y/2)/lc->x,
+ (itom[i].r.z+moldyn->dim.z/2)/lc->x,
+ neighbour);
+
+ for(j=0;j<27;j++) {
+
+ bc=(j<lc->dnlc)?0:1;
+
+#ifdef STATIC_LISTS
+ p=0;
+
+ while(neighbour[j][p]!=0) {
+
+ jtom=&(moldyn->atom[neighbour[j][p]]);
+ p++;
+#else
+ this=&(neighbour[j]);
+ list_reset_f(this);
+
+ if(this->start==NULL)
+ continue;
+
+ do {
+
+ jtom=this->current->data;
+#endif
+
+ /* process bond */
+ process(moldyn,&(itom[i]),jtom,data,bc);
+
+#ifdef STATIC_LISTS
+ }
+#else
+ } while(list_next_f(this)!=L_NO_NEXT_ELEMENT);
+#endif
+ }
+ }
+
+ return 0;
+
+}
+