1MOH:
reference: Structural bases for sulfide recognition in Lucina pectinata hemoglobin I., Rizzi M, Wittenberg JB, Coda A, Ascenzi P, Bolognesi M, J Mol Biol 1996 Apr 26;258(1):1-5. PMID: 8613980

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).