To examine whether error accumulation in these graphene nano-flakes is merely a function of molecular size, or whether extended conjugation may also play a role, we next examine analogous dimers of perhydrocircumcoronenes, which are the structures whose basic building block is cyclohexane rather than benzene. A structure for the dimer of [24]graphane (also known as perhydrocoronene, 107 C 24 H 36 ) was obtained from Ref. 78 and larger structures were constructed around it, maintaining the interlayer separation at 4.7 Å determined for (C 24 H 36 ) 2 . DLPNO errors for these graphane dimers are listed in Table , where they are juxtaposed with errors for graphene dimers having the same number of carbon atoms.