Materials Data on Ba5Sm8Mn4O21 by Materials Project
Ba5Sm8Mn4O21 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.66–3.33 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are two shorter (2.95 Å) and eight longer (3.01 Å) Ba–O bond lengths. 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 a cornercorner with one SmO7 pentagonal bipyramid, corners with two equivalent MnO5 trigonal bipyramids, edges with two equivalent MnO5 trigonal bipyramids, and faces with two equivalent SmO7 pentagonal bipyramids. There are a spread of Sm–O bond distances ranging from 2.38–2.49 Å. In the second Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sm–O bond distances ranging from 2.34–2.66 Å. Mn2+ is bonded to five O2- atoms to form distorted MnO5 trigonal bipyramids that share corners with two equivalent SmO7 pentagonal bipyramids and edges with two equivalent SmO7 pentagonal bipyramids. There are a spread of Mn–O bond distances ranging from 2.08–2.18 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, three Sm3+, and one Mn2+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, three Sm3+, and one Mn2+ atom. In the third O2- site, O2- is bonded to four equivalent Ba2+, one Sm3+, and one Mn2+ atom to form a mixture of distorted corner and edge-sharing OBa4SmMn octahedra. The corner-sharing octahedral tilt angles are 7°. In the fourth O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent Sm3+ atoms to form distorted corner-sharing OBa2Sm4 octahedra. The corner-sharing octahedral tilt angles are 0°.