4KP6:
reference: Discovery of triazines as potent, selective and orally active PDE4 inhibitors., Gewald R, Grunwald C, Egerland U, Bioorg Med Chem Lett. 2013 Aug 1;23(15):4308-14. doi: 10.1016/j.bmcl.2013.05.099., Epub 2013 Jun 10. PMID: 23806553

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