5ZIM:
reference: X-ray structure analysis of bacteriorhodopsin at 1.3 A resolution., Hasegawa N, Jonotsuka H, Miki K, Takeda K, Sci Rep. 2018 Sep 3;8(1):13123. doi: 10.1038/s41598-018-31370-0. PMID: 30177765

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