Nature of Ce-Ce interaction in CeB6 and its consequences

The interaction between nearest-neighbor Ce ions mediated by conduction ele ctrons is carefully analyzed for CeB6 by fully taking into account the symm etry connecting two Ce ions as well as the nature of Gamma(8) wave function s. It is shown that the interaction Hamiltonian resulting from the analysis has a simple form containing a very felv parameters because of constraints due to the symmetry. It is concluded quite generally from the interaction Hamiltonian that when the AF quadrupole-quadrupole interaction of Gamma(5)- type is strong. the AF octupole-octupole interaction of T-xyz type is equal ly strong. Thus the present analysis gives a strong support to the importan ce of T-xyz octupoles in CeB6.