Thumbnail: A diagram of an aromatic ring current. B0 is the applied magnetic field, the red arrow indicating its direction. The orange ring shows the direction of the ring current, and the purple...Thumbnail: A diagram of an aromatic ring current. B0 is the applied magnetic field, the red arrow indicating its direction. The orange ring shows the direction of the ring current, and the purple rings show the direction of the induced magnetic field. (Public Domain; Benjah-bmm27).