Peculiarities of the electronic structure of cubic and hexagonal modifications of Re O3

A transformation of the electronic structure of the cubic Re O3 I compound (structure of Pm3m type) during its transition into the hexagonal metastable high-temperature phase Re O3 III (structure of P6322 type) is studied by means of X-ray emission, absorption, and photoelectron spectroscopy methods. Energy diagrams of the distribution of valence states for the above modifications of Re O3 are constructed. It is found that, after termination at high pressures of the irreversible polymorphic transition Re O3 I → Rep3 III, a part of delocalized 0 2p-like states of π-type transforms into local-binding states of σ-type with a higher energy