The X-ray crystal structure of (Isomer 2 of Er2@C82)·NiII(OEP)·2(benzene) shows that the fullerene cage in Isomer 2 of Er2@C82 is the C3v isomer (82∶8) and that the erbium ions are distributed over 23 interior sites with occupancies ranging from 0.25 to 0.03.
