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La0.7Ca0.3MnO3 (a = 3.86 angstroms) epitaxial thin films have been grown on SrTiO3 (a = 3.905 angstroms), LaAlO3 (a = 3.79 angstroms), and YAlO3 (a/square root of 2 = 3.66 angstroms, b/square root of 2 = 3.77 angstroms) substrates. The films were analyzed with x-ray diffraction, x-ray photoemission spectroscopy, dc and ac resistivity, and dc magnetization.
CaMn2O4 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.68 Å. Mn3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 13–47°. There are a spread of Mn–O bond distances ranging from 1.94–2.52 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ca2+ and three equivalent Mn3+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Ca2+ and four equivalent Mn3+ atoms. In the third O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Mn3+ atoms to form distorted corner-sharing OCa2Mn2 tetrahedra.
Ca2Mn3O8 is Pyrite-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with seven MnO6 octahedra, edges with three MnO6 octahedra, and edges with two equivalent CaO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 20–56°. There are a spread of Ca–O bond distances ranging from 2.28–2.45 Å. There are two inequivalent Mn4+ sites. In the first Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six equivalent CaO6 pentagonal pyramids, edges with four equivalent MnO6 octahedra, and edges with two equivalent CaO6 pentagonal pyramids. There is four shorter (1.93 Å) and two longer (1.95 Å) Mn–O bond length. In the second Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent CaO6 pentagonal pyramids, edges with four MnO6 octahedra, and edges with two equivalent CaO6 pentagonal pyramids. There are a spread of Mn–O bond distances ranging from 1.90–2.03 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two equivalent Mn4+ atoms. In the second O2- site, O2- is bonded to one Ca2+ and three Mn4+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids. In the third O2- site, O2- is bonded to two equivalent Ca2+ and two Mn4+ atoms to form a mixture of distorted edge and corner-sharing OCa2Mn2 trigonal pyramids.
Ca4Mn2O7 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.95 Å. Mn3+ is bonded to five O2- atoms to form corner-sharing MnO5 square pyramids. There are a spread of Mn–O bond distances ranging from 1.88–2.08 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Mn3+ atoms to form a mixture of distorted edge and corner-sharing OCa4Mn2 octahedra. In the second O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Mn3+ atoms to form distorted OCa2Mn2 tetrahedra that share corners with two equivalent OCa4Mn2 octahedra, corners with two equivalent OCa2Mn2 tetrahedra, and an edgeedge with one OCa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 18–79°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five equivalent Ca2+ and one Mn3+ atom.
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.
Ca2MnO4 crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.63 Å. Mn4+ is bonded to six O2- atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 25°. There is four shorter (1.90 Å) and two longer (1.97 Å) Mn–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five equivalent Ca2+ and one Mn4+ atom to form a mixture of distorted edge and corner-sharing OCa5Mn octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Mn4+ atoms.
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.
CaMnO3 is Orthorhombic Perovskite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.64 Å. Mn4+ is bonded to six O2- atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 26–27°. There is two shorter (1.94 Å) and four longer (1.95 Å) Mn–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent Ca2+ and two equivalent Mn4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Mn4+ atoms.
CaMn2O4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with ten equivalent MnO5 square pyramids, edges with two equivalent CaO6 octahedra, and edges with two equivalent MnO5 square pyramids. There are a spread of Ca–O bond distances ranging from 2.38–2.43 Å. Mn3+ is bonded to five O2- atoms to form distorted MnO5 square pyramids that share corners with five equivalent CaO6 octahedra, corners with two equivalent MnO5 square pyramids, an edgeedge with one CaO6 octahedra, and edges with three equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 43–62°. There are a spread of Mn–O bond distances ranging from 1.94–2.23 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and three equivalent Mn3+ atoms to form a mixture of edge and corner-sharing OCaMn3 trigonal pyramids. In the second O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Mn3+ atoms to form a mixture of distorted edge and corner-sharing OCa2Mn2 trigonal pyramids.
CaMn16O32 is zeta iron carbide-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.64 Å. There are twelve inequivalent Mn+3.88+ sites. In the first Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.90–2.07 Å. In the second Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.89–1.97 Å. In the third Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.90–1.97 Å. In the fourth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.91–1.96 Å. In the fifth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.89–1.97 Å. In the sixth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of Mn–O bond distances ranging from 1.91–2.05 Å. In the seventh Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Mn–O bond distances ranging from 1.92–1.95 Å. In the eighth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.91–1.96 Å. In the ninth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 49–50°. There are a spread of Mn–O bond distances ranging from 1.90–2.00 Å. In the tenth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.91–1.99 Å. In the eleventh Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.91–1.96 Å. In the twelfth Mn+3.88+ site, Mn+3.88+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of Mn–O bond distances ranging from 1.92–1.96 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and three Mn+3.88+ atoms. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to three Mn+3.88+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to three Mn+3.88+ atoms. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to three Mn+3.88+ atoms. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.88+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the twentieth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.88+ atoms. In the twenty-first O2- site, O2- is bonded to one Ca2+ and three Mn+3.88+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.88+ atoms. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.88+ atoms. In the twenty-fourth O2- site, O2- is bonded to one Ca2+ and three Mn+3.88+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids.
CaMnO2 is Caswellsilverite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four equivalent MnO6 octahedra, edges with six equivalent CaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Ca–O bond distances ranging from 2.35–2.41 Å. Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with four equivalent CaO6 octahedra, edges with six equivalent CaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are a spread of Mn–O bond distances ranging from 2.24–2.43 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and four equivalent Mn2+ atoms to form a mixture of edge and corner-sharing OCa2Mn4 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. In the second O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Mn2+ atoms to form a mixture of edge and corner-sharing OCa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–3°.
CaMnO2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ca2+ is bonded to six equivalent O2- atoms to form CaO6 octahedra that share corners with six equivalent MnO6 octahedra, edges with six equivalent CaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Ca–O bond lengths are 2.37 Å. Mn2+ is bonded to six equivalent O2- atoms to form MnO6 octahedra that share corners with six equivalent CaO6 octahedra, edges with six equivalent CaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Mn–O bond lengths are 2.30 Å. O2- is bonded to three equivalent Ca2+ and three equivalent Mn2+ atoms to form a mixture of edge and corner-sharing OCa3Mn3 octahedra. The corner-sharing octahedral tilt angles are 0°.
CaMn4O8 is beta indium sulfide-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.42 Å. There are two inequivalent Mn+3.50+ sites. In the first Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–2.25 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–2.00 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mn+3.50+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three Mn+3.50+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.50+ atoms. In the fourth O2- site, O2- is bonded to one Ca2+ and three Mn+3.50+ atoms to form a mixture of distorted corner and edge-sharing OCaMn3 trigonal pyramids.
CaMnO2 is Caswellsilverite-like structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Ca2+ is bonded to six equivalent O2- atoms to form CaO6 octahedra that share corners with six equivalent MnO6 octahedra, edges with six equivalent CaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Ca–O bond lengths are 2.37 Å. Mn2+ is bonded to six equivalent O2- atoms to form MnO6 octahedra that share corners with six equivalent CaO6 octahedra, edges with six equivalent CaO6 octahedra, and edges with six equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Mn–O bond lengths are 2.30 Å. O2- is bonded to three equivalent Ca2+ and three equivalent Mn2+ atoms to form a mixture of corner and edge-sharing OCa3Mn3 octahedra. The corner-sharing octahedral tilt angles are 0°.
Ca4Mn4O11 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first 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 2.34–2.71 Å. In the second 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 2.33–2.80 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 2.33–2.74 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.57 Å. There are four inequivalent Mn+3.50+ sites. In the first Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra and corners with four equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 22–29°. There are a spread of Mn–O bond distances ranging from 1.90–1.98 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four equivalent MnO6 octahedra and a cornercorner with one MnO5 square pyramid. The corner-sharing octahedra tilt angles range from 16–34°. There are a spread of Mn–O bond distances ranging from 1.91–2.00 Å. In the third Mn+3.50+ site, Mn+3.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four equivalent MnO6 octahedra and a cornercorner with one MnO5 square pyramid. The corner-sharing octahedra tilt angles range from 24–31°. There are a spread of Mn–O bond distances ranging from 1.92–1.99 Å. In the fourth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra and corners with four equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 22–29°. There are a spread of Mn–O bond distances ranging from 1.90–2.02 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Mn+3.50+ atoms. In the second O2- site, O2- is bonded to three Ca2+ and two Mn+3.50+ atoms to form distorted OCa3Mn2 square pyramids that share corners with two equivalent OCa3Mn2 square pyramids and corners with two equivalent OCa2Mn2 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Mn+3.50+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Mn+3.50+ atoms. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Mn+3.50+ atoms. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Mn+3.50+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Mn+3.50+ atoms. In the eighth O2- site, O2- is bonded to two Ca2+ and two Mn+3.50+ atoms to form distorted corner-sharing OCa2Mn2 tetrahedra. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Mn+3.50+ atoms. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Mn+3.50+ atoms. In the eleventh O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Mn+3.50+ atoms.
CaMnO2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with four equivalent CaO6 octahedra, corners with eight equivalent MnO6 octahedra, edges with two equivalent MnO6 octahedra, edges with four equivalent CaO6 octahedra, and faces with two equivalent MnO6 octahedra. The corner-sharing octahedra tilt angles range from 42–52°. There are a spread of Ca–O bond distances ranging from 2.32–2.60 Å. Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent MnO6 octahedra, corners with eight equivalent CaO6 octahedra, edges with two equivalent CaO6 octahedra, edges with four equivalent MnO6 octahedra, and faces with two equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 42–51°. There are a spread of Mn–O bond distances ranging from 2.24–2.74 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to three equivalent Ca2+ and three equivalent Mn2+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to three equivalent Ca2+ and three equivalent Mn2+ atoms.
CaMn2O4 is Spinel structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with twelve MnO6 octahedra. The corner-sharing octahedra tilt angles range from 54–74°. There are two shorter (2.23 Å) and two longer (2.24 Å) Ca–O bond lengths. There are two inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six equivalent CaO4 tetrahedra and edges with six MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.94–2.42 Å. In the second Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six equivalent CaO4 tetrahedra and edges with six MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.95–2.42 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids. In the second O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids. In the third O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids. In the fourth O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form a mixture of distorted edge and corner-sharing OCaMn3 trigonal pyramids.
CaMn2O4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two 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 2.27–2.65 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 2.27–2.68 Å. There are four inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Mn–O bond distances ranging from 1.95–2.13 Å. In the second Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four MnO5 square pyramids and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.97–2.26 Å. In the third Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four MnO5 square pyramids and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.97–2.26 Å. In the fourth Mn3+ site, Mn3+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Mn–O bond distances ranging from 1.95–2.12 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Mn3+ atoms. In the second O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form distorted OCaMn3 tetrahedra that share corners with two equivalent OCa2Mn3 square pyramids, corners with two equivalent OCaMn3 tetrahedra, and edges with three OCa2Mn3 square pyramids. In the third O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form distorted OCaMn3 tetrahedra that share corners with two equivalent OCa2Mn3 square pyramids, corners with two equivalent OCaMn3 tetrahedra, and edges with three OCa2Mn3 square pyramids. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Mn3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Ca2+ and two equivalent Mn3+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Ca2+ and three Mn3+ atoms to form distorted OCa2Mn3 square pyramids that share corners with two equivalent OCaMn3 tetrahedra, edges with four OCa2Mn3 square pyramids, and edges with three OCaMn3 tetrahedra. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Ca2+ and two equivalent Mn3+ atoms. In the eighth O2- site, O2- is bonded to two equivalent Ca2+ and three Mn3+ atoms to form distorted OCa2Mn3 square pyramids that share corners with two equivalent OCaMn3 tetrahedra, edges with four OCa2Mn3 square pyramids, and edges with three OCaMn3 tetrahedra.