DOE OSTI2020
Ba4Eu3CeTl2(Cu2O9)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.67–2.98 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.66–2.98 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.66–3.00 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.66–3.00 Å. There are two inequivalent Eu3+ sites. In the first Eu3+ site, Eu3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Eu–O bond distances ranging from 2.32–2.54 Å. In the second Eu3+ site, Eu3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Eu–O bond distances ranging from 2.34–2.57 Å. Ce4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ce–O bond distances ranging from 2.24–2.54 Å. There are four inequivalent Cu+2.25+ sites. In the first Cu+2.25+ site, Cu+2.25+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share a cornercorner with one TlO6 octahedra and corners with four CuO5 square pyramids. The corner-sharing octahedral tilt angles are 4°. There are four shorter (1.95 Å) and one longer (2.61 Å) Cu–O bond lengths. In the second Cu+2.25+ site, Cu+2.25+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share a cornercorner with one TlO6 octahedra and corners with four CuO5 square pyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of Cu–O bond distances ranging from 1.94–2.59 Å. In the third Cu+2.25+ site, Cu+2.25+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share a cornercorner with one TlO6 octahedra and corners with four CuO5 square pyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of Cu–O bond distances ranging from 1.94–2.61 Å. In the fourth Cu+2.25+ site, Cu+2.25+ is bonded to five O2- atoms to form distorted CuO5 square pyramids that share a cornercorner with one TlO6 octahedra and corners with four CuO5 square pyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of Cu–O bond distances ranging from 1.94–2.61 Å. There are two inequivalent Tl3+ sites. In the first Tl3+ site, Tl3+ is bonded to six O2- atoms to form distorted TlO6 octahedra that share corners with four equivalent TlO6 octahedra, corners with two CuO5 square pyramids, and edges with four TlO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Tl–O bond distances ranging from 2.12–2.89 Å. In the second Tl3+ site, Tl3+ is bonded to six O2- atoms to form distorted TlO6 octahedra that share corners with four equivalent TlO6 octahedra, corners with two CuO5 square pyramids, and edges with four TlO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Tl–O bond distances ranging from 2.12–2.89 Å. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, two equivalent Eu3+, and two equivalent Cu+2.25+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, two equivalent Eu3+, and two equivalent Cu+2.25+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent Eu3+, and two Cu+2.25+ atoms. Both O–Eu bond lengths are 2.54 Å. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent Eu3+, and two Cu+2.25+ atoms. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, one Eu3+, one Ce4+, and two equivalent Cu+2.25+ atoms. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, one Eu3+, one Ce4+, and two equivalent Cu+2.25+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, two equivalent Ce4+, and two Cu+2.25+ atoms. In the eighth O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ba2+, two equivalent Eu3+, and two Cu+2.25+ atoms. In the ninth O2- site, O2- is bonded to two Ba2+ and four Tl3+ atoms to form a mixture of corner and edge-sharing OBa2Tl4 octahedra. The corner-sharing octahedral tilt angles are 6°. In the tenth O2- site, O2- is bonded to two Ba2+ and four Tl3+ atoms to form a mixture of corner and edge-sharing OBa2Tl4 octahedra. The corner-sharing octahedral tilt angles are 6°. In the eleventh O2- site, O2- is bonded to four Ba2+, one Cu+2.25+, and one Tl3+ atom to form a mixture of distorted corner and edge-sharing OBa4TlCu octahedra. The corner-sharing octahedra tilt angles range from 9–23°. In the twelfth O2- site, O2- is bonded to four Ba2+, one Cu+2.25+, and one Tl3+ atom to form a mixture of distorted corner and edge-sharing OBa4TlCu octahedra. The corner-sharing octahedra tilt angles range from 9–23°. In the thirteenth O2- site, O2- is bonded to four Ba2+, one Cu+2.25+, and one Tl3+ atom to form a mixture of distorted corner and edge-sharing OBa4TlCu octahedra. The corner-sharing octahedra tilt angles range from 9–23°. In the fourteenth O2- site, O2- is bonded to four Ba2+, one Cu+2.25+, and one Tl3+ atom to form a mixture of distorted corner and edge-sharing OBa4TlCu octahedra. The corner-sharing octahedra tilt angles range from 9–23°. In the fifteenth O2- site, O2- is bonded to two equivalent Eu3+ and two equivalent Ce4+ atoms to form OCe2Eu2 tetrahedra that share corners with four OCe2Eu2 tetrahedra and edges with four equivalent OCeEu3 tetrahedra. In the sixteenth O2- site, O2- is bonded to four Eu3+ atoms to form OEu4 tetrahedra that share corners with four OCe2Eu2 tetrahedra and edges with four equivalent OCeEu3 tetrahedra. In the seventeenth O2- site, O2- is bonded to three Eu3+ and one Ce4+ atom to form OCeEu3 tetrahedra that share corners with four equivalent OCeEu3 tetrahedra and edges with four OCe2Eu2 tetrahedra.