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DOE OSTI · 1751531

Materials Data on CaMgZn by Materials Project

Abstract

MgZnCa crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca, seven Mg, and five Zn atoms. There are one shorter (3.57 Å) and two longer (3.62 Å) Ca–Ca bond lengths. There are a spread of Ca–Mg bond distances ranging from 3.45–3.51 Å. There are a spread of Ca–Zn bond distances ranging from 3.32–3.54 Å. In the second Ca site, Ca is bonded in a 12-coordinate geometry to four Ca, five Mg, and seven Zn atoms. The Ca–Ca bond length is 3.44 Å. There are a spread of Ca–Mg bond distances ranging from 3.36–3.54 Å. There are a spread of Ca–Zn bond distances ranging from 3.39–3.51 Å. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six Ca, two equivalent Mg, and four Zn atoms to form distorted MgCa6Mg2Zn4 cuboctahedra that share corners with two equivalent ZnCa6Mg6 cuboctahedra, corners with four equivalent MgCa6Mg4Zn2 cuboctahedra, edges with six equivalent MgCa6Mg2Zn4 cuboctahedra, faces with three equivalent ZnCa6Mg6 cuboctahedra, and faces with eight MgCa6Mg2Zn4 cuboctahedra. Both Mg–Mg bond lengths are 3.10 Å. There are a spread of Mg–Zn bond distances ranging from 2.90–3.06 Å. In the second Mg site, Mg is bonded to six Ca, four Mg, and two equivalent Zn atoms to form distorted MgCa6Mg4Zn2 cuboctahedra that share corners with eight MgCa6Mg2Zn4 cuboctahedra, edges with two equivalent MgCa6Mg4Zn2 cuboctahedra, faces with four equivalent ZnCa6Mg6 cuboctahedra, and faces with ten MgCa6Mg2Zn4 cuboctahedra. There are one shorter (2.93 Å) and one longer (3.02 Å) Mg–Mg bond lengths. There are one shorter (2.85 Å) and one longer (3.00 Å) Mg–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded to six Ca and six Mg atoms to form distorted ZnCa6Mg6 cuboctahedra that share corners with four equivalent MgCa6Mg2Zn4 cuboctahedra, corners with four equivalent ZnCa6Mg6 cuboctahedra, edges with two equivalent ZnCa6Mg6 cuboctahedra, and faces with fourteen MgCa6Mg2Zn4 cuboctahedra. In the second Zn site, Zn is bonded in a 2-coordinate geometry to six Ca, two equivalent Mg, and two Zn atoms. There are one shorter (2.74 Å) and one longer (2.77 Å) Zn–Zn bond lengths. In the third Zn site, Zn is bonded in a 12-coordinate geometry to six Ca, two equivalent Mg, and two equivalent Zn atoms.

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2020-05-03. Materials Data on CaMgZn by Materials Project. https://doi.org/10.17188/1751531

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