  The paramagnetic phase diagram of the Hubbard model with nearest-neighbor
(NN) and next-nearest-neighbor (NNN) hopping on the Bethe lattice is computed
at half-filling and in the weakly doped regime using the self-energy functional
approach for dynamical mean-field theory. NNN hopping breaks the particle-hole
symmetry and leads to a strong asymmetry of the electron-doped and hole-doped
regimes. Phase separation occurs at and near half-filling, and the critical
temperature of the Mott transition is strongly suppressed.
