Materials Data on Ca21(Zn18Ni)2 by Materials Project

Abstract

Ca21Ni2Zn36 is Hexagonal Laves-derived structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. there are four inequivalent Ca sites. In the first Ca site, Ca is bonded in a hexagonal planar geometry to six equivalent Zn atoms. All Ca–Zn bond lengths are 3.17 Å. In the second Ca site, Ca is bonded in a 10-coordinate geometry to ten Zn atoms. There are a spread of Ca–Zn bond distances ranging from 3.22–3.37 Å. In the third Ca site, Ca is bonded in a 12-coordinate geometry to twelve Zn atoms. There are a spread of Ca–Zn bond distances ranging from 3.12–3.25 Å. In the fourth Ca site, Ca is bonded in a 12-coordinate geometry to twelve equivalent Zn atoms. All Ca–Zn bond lengths are 3.15 Å. Ni is bonded to twelve Zn atoms to form NiZn12 cuboctahedra that share corners with six equivalent ZnCa5Zn6Ni cuboctahedra and faces with twelve ZnCa5Zn6Ni cuboctahedra. There are six shorter (2.55 Å) and six longer (2.65 Å) Ni–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a 10-coordinate geometry to seven Ca and three Zn atoms. There are one shorter (2.72 Å) and two longer (2.91 Å) Zn–Zn bond lengths. In the second Zn site, Zn is bonded to five Ca, one Ni, and six Zn atoms to form ZnCa5Zn6Ni cuboctahedra that share corners with seven ZnCa5Zn6Ni cuboctahedra, edges with three equivalent ZnCa5Zn6Ni cuboctahedra, a faceface with one NiZn12 cuboctahedra, and faces with thirteen ZnCa5Zn6Ni cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.65–2.77 Å. In the third Zn site, Zn is bonded to five Ca, one Ni, and six Zn atoms to form distorted ZnCa5Zn6Ni cuboctahedra that share a cornercorner with one NiZn12 cuboctahedra, corners with five ZnCa5Zn6Ni cuboctahedra, edges with two equivalent ZnCa5Zn6Ni cuboctahedra, a faceface with one NiZn12 cuboctahedra, and faces with eighteen ZnCa5Zn6Ni cuboctahedra. There are one shorter (2.57 Å) and two longer (2.78 Å) Zn–Zn bond lengths.