were fixed during refinement of the X-ray diffraction data (i.e., they were not determined experimentally; see discussion above). This result explains why an averaging of calculated 1 J CC values obtained from Sets 1 and 2 are in better agreement with the experimental 1 J CC values than the calculated 1 J CC values obtained from either Sets 3 and 4. A second set of DFT calculations was conducted on 1 c using the B3LYP and wB97XD functionals and the 6-311+g(d,p) basis set in which C1-H1 and C2-H2 bond lengths were fixed at 1.120 A and the heavy atoms were fixed to the crystal geometry of 1 . The calculated 1 J C1,C2