Finding intermodel H-bonds Finding intramodel H-bonds Constraints relaxed by 0.4 angstroms and 20 degrees Models used: #0 5y21_C.cif H-bonds (donor, acceptor, hydrogen, D..A dist, D-H..A dist): ARG 3.A NH1 GLU 1.A OE1 no hydrogen 2.637 N/A ARG 3.A NH2 GLU 1.A OE1 no hydrogen 2.852 N/A