Ortho-and para-linked benzenes are wellknown to have fairly high single-molecule conductance (see transmission plot in Figure ). Consequently, the current is around a nanoampere at a bias of 100 mV. Despite the small ring diameter of benzene, the magnetic field in both the ortho-and para-linked systems is weak because the ring current runs both ways around the benzene ring. In the ortho-connected case the ring current that takes the long way around the ring dominates, and a unidirectional µT magnetic field is formed inside the benzene ring. In the para-connected case the two-way ring current cancels the magnetic field inside the benzene ring.