Materials Data on Ca3Mn2O7 by Materials Project

Abstract

Ca3Mn2O7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.21–2.59 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.85 Å. In the third Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.64 Å. There are two inequivalent Mn4+ sites. In the first Mn4+ site, Mn4+ is bonded to five O2- atoms to form corner-sharing MnO5 trigonal bipyramids. There are a spread of Mn–O bond distances ranging from 1.83–1.91 Å. In the second Mn4+ site, Mn4+ is bonded to five O2- atoms to form corner-sharing MnO5 square pyramids. There are a spread of Mn–O bond distances ranging from 1.84–1.93 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Mn4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Mn4+ atoms. In the third O2- site, O2- is bonded to two Ca2+ and two Mn4+ atoms to form a mixture of distorted corner and edge-sharing OCa2Mn2 tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Mn4+ atom. In the fifth O2- site, O2- is bonded to four Ca2+ and one Mn4+ atom to form distorted OCa4Mn square pyramids that share corners with three OCa4Mn square pyramids, corners with two equivalent OCa2Mn2 tetrahedra, corners with two equivalent OCa4Mn trigonal bipyramids, edges with two equivalent OCa4Mn square pyramids, an edgeedge with one OCa2Mn2 tetrahedra, and edges with two equivalent OCa4Mn trigonal bipyramids. In the sixth O2- site, O2- is bonded to four Ca2+ and one Mn4+ atom to form distorted OCa4Mn trigonal bipyramids that share corners with three OCa4Mn square pyramids, corners with two equivalent OCa2Mn2 tetrahedra, corners with two equivalent OCa4Mn trigonal bipyramids, edges with four OCa4Mn square pyramids, and an edgeedge with one OCa2Mn2 tetrahedra. In the seventh O2- site, O2- is bonded to four Ca2+ and one Mn4+ atom to form distorted OCa4Mn square pyramids that share corners with three OCa4Mn square pyramids, a cornercorner with one OCa2Mn2 tetrahedra, a cornercorner with one OCa4Mn trigonal bipyramid, edges with two equivalent OCa4Mn square pyramids, an edgeedge with one OCa2Mn2 tetrahedra, and edges with two equivalent OCa4Mn trigonal bipyramids.