5TUX:
reference: Photoactivation mechanism of a carotenoid-based photoreceptor., Bandara S, Ren Z, Lu L, Zeng X, Shin H, Zhao KH, Yang X, Proc Natl Acad Sci U S A. 2017 Jun 13;114(24):6286-6291. doi:, 10.1073/pnas.1700956114. Epub 2017 May 30. PMID: 28559328

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