Reaction of solids of pure D-2d and D-2 C-84, as well as mixtures of these isomers, with an excess of potassium produces the cubic phases K8+xC84, With multiple occupancy of the octahedral site by potassium. Analysis of X-ray powder diffraction data reveals that the anions adopt well-defined orientations in the solid, driven by the anion-cation contacts. Electron paramagnetic resonance measurements on the solid fullerides indicate that the electronic properties depend on the particular isomer of C-84 used as host.