Materials Data on Mg21Zn25 by Materials Project
Mg21Zn25 is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to eight Mg and four Zn atoms. There are a spread of Mg–Mg bond distances ranging from 3.05–3.24 Å. There are two shorter (2.90 Å) and two longer (2.93 Å) Mg–Zn bond lengths. In the second Mg site, Mg is bonded in a 7-coordinate geometry to six Mg and eight Zn atoms. There are a spread of Mg–Mg bond distances ranging from 2.98–3.39 Å. There are a spread of Mg–Zn bond distances ranging from 2.93–3.25 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to four Mg and twelve Zn atoms. There are a spread of Mg–Mg bond distances ranging from 3.06–3.21 Å. There are a spread of Mg–Zn bond distances ranging from 3.03–3.14 Å. In the fourth Mg site, Mg is bonded in a 7-coordinate geometry to six Mg and seven Zn atoms. There are a spread of Mg–Zn bond distances ranging from 2.92–3.00 Å. There are six inequivalent Zn sites. In the first Zn site, Zn is bonded to seven Mg and five Zn atoms to form a mixture of edge, face, and corner-sharing ZnMg7Zn5 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.62–2.70 Å. In the second Zn site, Zn is bonded to seven Mg and five Zn atoms to form a mixture of edge, face, and corner-sharing ZnMg7Zn5 cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.55–2.63 Å. In the third Zn site, Zn is bonded to six equivalent Mg and six Zn atoms to form a mixture of edge, face, and corner-sharing ZnMg6Zn6 cuboctahedra. There are two shorter (2.67 Å) and two longer (2.69 Å) Zn–Zn bond lengths. In the fourth Zn site, Zn is bonded to six equivalent Mg and six equivalent Zn atoms to form a mixture of edge, face, and corner-sharing ZnMg6Zn6 cuboctahedra. In the fifth Zn site, Zn is bonded to seven Mg and five Zn atoms to form a mixture of distorted edge, face, and corner-sharing ZnMg7Zn5 cuboctahedra. There are one shorter (2.58 Å) and one longer (2.65 Å) Zn–Zn bond lengths. In the sixth Zn site, Zn is bonded to eight Mg and four Zn atoms to form ZnMg8Zn4 cuboctahedra that share corners with eight ZnMg7Zn5 cuboctahedra, edges with two equivalent ZnMg8Zn4 cuboctahedra, and faces with fourteen ZnMg7Zn5 cuboctahedra.