Consider a single crystal of copper (FCC) and a single crystal of zinc (HCP). The cubic structure is isotropic with respect to electrical conductivity while the hexagonal single crystal is anisotropic, i.e. the electrical properties of the material differ within the basal plane compared to along the c-axis of the crystal (electrical properties along a = b but ). Starting with = where q is the charge density, which is a conserved quantity so that / =

What is the relationship between and the Flux (J) in these materials for a potential gradient applied neither along the c-axis nor in the basal plane?