5FEC:
reference: Structural basis for germline antibody recognition of HIV-1 immunogens., Scharf L, West AP, Sievers SA, Chen C, Jiang S, Gao H, Gray MD, McGuire AT, Scheid JF, Nussenzweig MC, Stamatatos L, Bjorkman PJ, Elife. 2016 Mar 21;5. pii: e13783. doi: 10.7554/eLife.13783. PMID: 26997349

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