DOE OSTI2020
Re2O7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Re7+ sites. In the first Re7+ site, Re7+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and corners with five OO5 square pyramids. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Re–O bond distances ranging from 1.82–2.03 Å. In the second Re7+ site, Re7+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and corners with five OO5 square pyramids. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Re–O bond distances ranging from 1.83–2.03 Å. In the third Re7+ site, Re7+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and corners with five OO5 square pyramids. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Re–O bond distances ranging from 1.83–2.02 Å. In the fourth Re7+ site, Re7+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and corners with five OO5 square pyramids. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Re–O bond distances ranging from 1.83–2.03 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to five O2- atoms to form OO5 square pyramids that share corners with ten ReO6 octahedra. The corner-sharing octahedra tilt angles range from 64–75°. There are a spread of O–O bond distances ranging from 3.13–3.22 Å. In the second O2- site, O2- is bonded to five O2- atoms to form distorted OO5 square pyramids that share corners with ten ReO6 octahedra. The corner-sharing octahedra tilt angles range from 64–75°. There are a spread of O–O bond distances ranging from 3.15–3.23 Å. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two Re7+ and one O2- atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two Re7+ and one O2- atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Re7+ and one O2- atom.