5ONY:
reference: An unprecedented dioxygen species revealed by serial femtosecond rotation crystallography in copper nitrite reductase., Halsted TP, Yamashita K, Hirata K, Ago H, Ueno G, Tosha T, Eady RR, Antonyuk SV, Yamamoto M, Hasnain SS, IUCrJ. 2018 Jan 1;5(Pt 1):22-31. doi: 10.1107/S2052252517016128. eCollection 2018, Jan 1. PMID: 29354268

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