Finding intermodel H-bonds Finding intramodel H-bonds Constraints relaxed by 0.4 angstroms and 20 degrees Models used: #0 1re3_H.cif H-bonds (donor, acceptor, hydrogen, D..A dist, D-H..A dist): HIS 2.A N HIS 2.A ND1 no hydrogen 2.728 N/A ARG 3.A NE HIS 2.A O no hydrogen 3.526 N/A