+
+int tersoff_mult_check_2b_bond(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
+
+ t_tersoff_mult_params *params;
+ t_3dvec dist;
+ double d;
+ u8 brand;
+
+ v3_sub(&dist,&(aj->r),&(ai->r));
+ if(bc) check_per_bound(moldyn,&dist);
+ d=v3_absolute_square(&dist);
+
+ params=moldyn->pot_params;
+ brand=ai->brand;
+
+ if(brand==aj->brand) {
+ if(d<=params->S2[brand])
+ return TRUE;
+ }
+ else {
+ if(d<=params->S2mixed)
+ return TRUE;
+ }
+
+ return FALSE;
+}
+