On the optical properties and low pressure-induced spin transition in magnetite from ab initio calculations

► LDA+U calculations are performed on the high-temperature phase of magnetite. ► The electrical anomaly observed in the high-temperature phase of magnetite under pressure is discussed. ► We suggest the transition may be related to the formation of an inhomogeneous mixed-spin state system HS→HS/LS with cations in octahedral sites.