DOI: 10.17188/1662975
title: Materials Data on Sr7Mn7O20 by Materials Project

description: Sr7Mn7O20 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. there are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with nine SrO12 cuboctahedra, faces with five SrO12 cuboctahedra, faces with six MnO6 octahedra, and faces with two equivalent MnO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.62–3.04 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with seven SrO12 cuboctahedra, faces with four SrO12 cuboctahedra, faces with six MnO6 octahedra, and faces with two equivalent MnO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.61–3.02 Å. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with ten SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight MnO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.69–2.84 Å. In the fourth Sr2+ site, Sr2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.61–2.75 Å. There are four inequivalent Mn+3.71+ sites. In the first Mn+3.71+ site, Mn+3.71+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with five MnO6 octahedra, a cornercorner with one MnO5 square pyramid, and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Mn–O bond distances ranging from 1.93–2.05 Å. In the second Mn+3.71+ site, Mn+3.71+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with five MnO6 octahedra, a cornercorner with one MnO5 square pyramid, and faces with six SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–11°. There are a spread of Mn–O bond distances ranging from 1.90–2.02 Å. In the third Mn+3.71+ site, Mn+3.71+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with three MnO6 octahedra, corners with two equivalent MnO5 square pyramids, and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–17°. There are a spread of Mn–O bond distances ranging from 1.91–1.97 Å. In the fourth Mn+3.71+ site, Mn+3.71+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO6 octahedra, corners with two equivalent MnO5 square pyramids, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–11°. There is four shorter (1.94 Å) and two longer (1.99 Å) Mn–O bond length. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sr2+ and two equivalent Mn+3.71+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Mn+3.71+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two Mn+3.71+ atoms. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two Mn+3.71+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Mn+3.71+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two Mn+3.71+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Mn+3.71+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Mn+3.71+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Mn+3.71+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Mn+3.71+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two equivalent Mn+3.71+ atoms.