4I91:
reference: Structural and Thermodynamic Basis of (+)-alpha-Pinene Binding to Human Cytochrome P450 2B6., Wilderman PR, Shah MB, Jang HH, Stout CD, Halpert JR, J Am Chem Soc. 2013 Jul 17;135(28):10433-40. doi: 10.1021/ja403042k. Epub 2013, Jul 3. PMID: 23786449

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