Phase diagram of the half-filled 3D Hubbard model

The antiferromagnetic Ne\'el temperature TN is calculated as a function of the Coulomb interaction U for a half-filled 3D Hubbard model. Numerical results are given for the specific heat and staggered magnetic suspectibility on periodic lattices ranging from 4³--10³ sites, and used to determine TN. The size dependence of the results suggests that the transition is weakly first order at small to intermediate values of U.