Metamagnetic transition and magnetic properties ofUPt3

We report fully relativistic band structure and total energy studies of ${\mathrm{UPt}}_3$ in the different magnetic states. We find that the ground state of ${\mathrm{Upt}}_3$ is nonmagentic, even though stable ferromagnetic and antiferromagnetic solutions are also found. We find that the total energy calculations 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.