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DOE OSTI2020

Materials Data on Ca3Mn2O7 by Materials Project

Ca3Mn2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.62 Å. In the second 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 2.29–2.55 Å. Mn4+ is bonded to six O2- atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 24–26°. There are a spread of Mn–O bond distances ranging from 1.93–1.96 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Ca2+ and one Mn4+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent Mn4+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent Mn4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Mn4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca3Mn2O7 by Materials Project

Ca3Mn2O7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with four equivalent CaO12 cuboctahedra, faces with four equivalent CaO12 cuboctahedra, and faces with eight equivalent MnO6 octahedra. There are four shorter (2.68 Å) and eight longer (2.69 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.70 Å. Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with five equivalent MnO6 octahedra and faces with four equivalent CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–2°. There is five shorter (1.90 Å) and one longer (1.94 Å) Mn–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ca2+ and two equivalent Mn4+ atoms. In the second O2- site, O2- is bonded to five equivalent Ca2+ and one Mn4+ atom to form a mixture of distorted corner and edge-sharing OCa5Mn octahedra. The corner-sharing octahedral tilt angles are 12°. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ca2+ and two equivalent Mn4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca3Mn2O7 by Materials Project

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.

36 MATERIALS SCIENCE↗