Quasiparticle bands and structural phase transition of iron from Gutzwiller density-functional theory

We use the Gutzwiller density-functional theory to calculate ground-state properties and band structures of iron in its body-centered-cubic (bcc) and hexagonal-close-packed (hcp) phases. For a Hubbard interaction U=9 eV and Hund's-rule coupling J=0.54 eV, we reproduce the lattice parameter, magnetic moment, and bulk modulus of bcc iron. For these parameters, bcc is the ground-state lattice structure at ambient pressure up to a pressure of pc=41GPa where a transition to the nonmagnetic hcp structure is predicted, in qualitative agreement with experiment(pexpc=10,...,15GPa). The calculated band structure for bcc iron is in good agreement with ARPES measurements. The agreement improves when we perturbatively include the spin-orbit coupling.