Materials Data on BaSm2CuO5 by Materials Project

Abstract

Sm2BaCuO5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 1-coordinate geometry to eleven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.63–3.35 Å. There are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded to seven O2- atoms to form distorted SmO7 pentagonal bipyramids that share corners with five equivalent CuO5 square pyramids, edges with five SmO7 pentagonal bipyramids, an edgeedge with one CuO5 square pyramid, and a faceface with one SmO7 pentagonal bipyramid. There are a spread of Sm–O bond distances ranging from 2.36–2.45 Å. In the second Sm3+ site, Sm3+ is bonded to seven O2- atoms to form distorted SmO7 pentagonal bipyramids that share corners with four equivalent SmO7 pentagonal bipyramids, edges with three equivalent SmO7 pentagonal bipyramids, edges with two equivalent CuO5 square pyramids, a faceface with one SmO7 pentagonal bipyramid, and a faceface with one CuO5 square pyramid. There are a spread of Sm–O bond distances ranging from 2.38–2.43 Å. Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with five equivalent SmO7 pentagonal bipyramids, edges with three SmO7 pentagonal bipyramids, and a faceface with one SmO7 pentagonal bipyramid. There are a spread of Cu–O bond distances ranging from 2.01–2.33 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Ba2+, two Sm3+, and one Cu2+ atom to form a mixture of distorted corner and edge-sharing OBa3Sm2Cu octahedra. The corner-sharing octahedral tilt angles are 4°. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, three Sm3+, and one Cu2+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, three Sm3+, and one Cu2+ atom.