Materials Data on Sr9Mg38 by Materials Project

Abstract

Mg38Sr9 is Hexagonal Laves-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 10-coordinate geometry to fourteen Mg atoms. There are a spread of Sr–Mg bond distances ranging from 3.65–3.91 Å. In the second Sr site, Sr is bonded in a 12-coordinate geometry to twelve Mg atoms. There are a spread of Sr–Mg bond distances ranging from 3.59–3.80 Å. There are ten inequivalent Mg sites. In the first Mg site, Mg is bonded to four equivalent Sr and eight Mg atoms to form MgSr4Mg8 cuboctahedra that share corners with four equivalent MgSr4Mg8 cuboctahedra, edges with two equivalent MgMg7 hexagonal pyramids, and faces with eight MgSr4Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.06–3.32 Å. In the second Mg site, Mg is bonded in a 10-coordinate geometry to three Sr and seven Mg atoms. There are a spread of Mg–Mg bond distances ranging from 3.13–3.25 Å. In the third Mg site, Mg is bonded to four Sr and eight Mg atoms to form MgSr4Mg8 cuboctahedra that share corners with four MgSr4Mg8 cuboctahedra, edges with two equivalent MgMg7 hexagonal pyramids, and faces with seven MgSr4Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 2.97–3.24 Å. In the fourth Mg site, Mg is bonded in a distorted q6 geometry to two equivalent Sr and ten Mg atoms. There are a spread of Mg–Mg bond distances ranging from 3.10–3.17 Å. In the fifth Mg site, Mg is bonded in a distorted q6 geometry to three equivalent Sr and nine Mg atoms. There are a spread of Mg–Mg bond distances ranging from 3.13–3.25 Å. In the sixth Mg site, Mg is bonded in a distorted q6 geometry to three equivalent Sr and nine Mg atoms. All Mg–Mg bond lengths are 3.23 Å. In the seventh Mg site, Mg is bonded in a 10-coordinate geometry to three Sr and seven Mg atoms. There are one shorter (3.11 Å) and one longer (3.36 Å) Mg–Mg bond lengths. In the eighth Mg site, Mg is bonded in a 10-coordinate geometry to three equivalent Sr and seven Mg atoms. The Mg–Mg bond length is 3.21 Å. In the ninth Mg site, Mg is bonded to seven Mg atoms to form distorted edge-sharing MgMg7 hexagonal pyramids. In the tenth Mg site, Mg is bonded in a distorted q6 geometry to three equivalent Sr and nine Mg atoms.