Metal-insulator transition and local-moment collapse in FeO under pressure

Abstract: We employ a combination of the \emph{ab initio} band structure methods and dynamical mean-field theory to determine the electronic structure and phase stability of paramagnetic FeO at high pressure and temperature. Our results reveal a high-spin to low-spin transition within the B1 crystal structure of FeO upon compression of the lattice volume above 73~GPa. The spin-state transition is accompanied by an orbital-selective Mott metal-insulator transition (MIT). The lattice volume is found to collapse by about 8.5~\% at the MIT, implying a complex interplay between electronic and lattice degrees of freedom. Our results for the electronic structure and lattice properties are in overall good agreement with experimental data.