The x-ray crystal structure PDB ID 7SI9 of Nirmatrelvir bound the SARS-Cov-2 was used for docking and also in validating the docked pose. The computational docked pose is close to that of the complete x-ray structure, including the eclipsed trifluoromethyl group. The docked pose overlayed with the 7SI9 ligand is illustrated in Figure . The trifluoromethyl is in an eclipsed position which is unusual because typically this is higher in energy than non-eclipsed. Studies of these groups have been done with this eclipsed position and found to be more stable in classes of compounds . This is the highest scoring docked Nirmatrelvir/Mpro pose generated by CCDC GOLD out of multiple runs. The RMSD of the 2 molecules in Figure is 2.89 Angstroms as calculated in PyMol, comparable to the 2 A x-ray resolution. The SARS-Cov-2 3CL protease (Mpro) binding site is an X-shaped cavity which can be described as: 3 ends are caves and the fourth is an exiting valley. This is the region of the Mpro relevant to viral replication which is targeted and partly blocked by Nirmatrelvir. This molecule, when bound, primarily fills in 2 caves.