METAMAGNETIC TRANSITION AND MAGNETIC-PROPERTIES OF UPT3

We report fully relativistic band structure and total energy studies o f UPt3 in the different magnetic states. We find that the ground state of UPt3 is nonmagnetic, even though stable ferromagnetic and antiferr omagnetic solutions are also found. We find that the total energy calc ulations predict the direction of the ordered moment correctly and for the first time the ''metamagnetic transition'' is found from a first principles total energy calculation for heavy fermion compounds.