  The electronic and magnetic properties of recently discovered new important
constituent of the Earth's lower mantle FeO2H were investigated by means of the
density functional theory combined with the dynamical mean field theory
(DFT+DMFT). Addition of the hydrogen to the parent FeO2 compound, which is an
uncorrelated bad metal, destroys the most important ingredient of its
electronic structure - O-O molecular orbitals. In effect physical properties of
FeO2 and FeO2H turn to be completely different, FeO2H is a correlated metal
with a mass renormalization, m*/m ~ 2, and magnetic moments on Fe ions become
well localized with the Curie-Weiss type of uniform magnetic susceptibility.
