4L6C:
reference: Conformationally constrained nucleoside phosphonic acids - potent inhibitors of human mitochondrial and cytosolic 5'(3')-nucleotidases., Simak O, Pachl P, Fabry M, Budesinsky M, Jandusik T, Hnizda A, Sklenickova R, Petrova M, Veverka V, Rezacova P, Brynda J, Rosenberg I, Org Biomol Chem. 2014 Sep 1. PMID: 25178098

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