  Electrical conductivity of FeO was measured up to 141 GPa and 2480 K in a
laserheated diamond-anvil cell. The results show that rock-salt (B1) type
structured FeO metallizes at around 70 GPa and 1900 K without any structural
phase transition. We computed fully self-consistently the electronic structure
and the electrical conductivity of B1 FeO as a function of pressure and
temperature, and found that although insulating as expected at ambient
condition, B1 FeO metallizes at high temperatures, consistent with experiments.
The observed metallization is related to spin crossover.
