4H8I:
reference: A photoswitchable neurotransmitter analogue bound to its receptor., Reiter A, Skerra A, Trauner D, Schiefner A, Biochemistry. 2013 Dec 17;52(50):8972-4. doi: 10.1021/bi4014402. Epub 2013 Dec 6. PMID: 24295282

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