struct BONDS { int n; // number of bonds <-- snip --> int *ia; // ia[n] : particle index of one end of the bond int *ib; // ib[n] : particle index of the other end of the bond }; struct BONDS_GROUP { int np; // number of particles in this group int *ip; // ip[np] : particle index of the group particles int *bonds; // bonds[np-1] : independent bond list }; struct BONDS_GROUPS { int n; // number of groups struct BONDS_GROUP **group; // grp[ng] };(NOTE: this is still in development and not imported into libstokes yet.)