Materials Data on Sr3(Cu2Sn)4 by Materials Project

Abstract

Sr3Cu8Sn4 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Sr is bonded in a 12-coordinate geometry to eight Cu and six Sn atoms. There are a spread of Sr–Cu bond distances ranging from 3.28–3.67 Å. There are a spread of Sr–Sn bond distances ranging from 3.37–3.46 Å. There are four inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to four equivalent Sr, four Cu, and four Sn atoms. There are two shorter (2.65 Å) and two longer (2.75 Å) Cu–Cu bond lengths. There are a spread of Cu–Sn bond distances ranging from 2.80–3.02 Å. In the second Cu site, Cu is bonded to two equivalent Sr, seven Cu, and three equivalent Sn atoms to form distorted CuSr2Cu7Sn3 cuboctahedra that share corners with four equivalent CuSr2Cu7Sn3 cuboctahedra, corners with five equivalent SnSr4Cu8 cuboctahedra, faces with six equivalent SnSr4Cu8 cuboctahedra, and faces with eight CuSr2Cu7Sn3 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.53–2.76 Å. There are one shorter (2.74 Å) and two longer (2.77 Å) Cu–Sn bond lengths. In the third Cu site, Cu is bonded in a distorted q6 geometry to six equivalent Sr and four Sn atoms. There are three shorter (2.75 Å) and one longer (2.76 Å) Cu–Sn bond lengths. In the fourth Cu site, Cu is bonded to nine Cu and three equivalent Sn atoms to form CuCu9Sn3 cuboctahedra that share corners with three equivalent SnSr4Cu8 cuboctahedra, faces with six equivalent SnSr4Cu8 cuboctahedra, and faces with eight CuSr2Cu7Sn3 cuboctahedra. All Cu–Sn bond lengths are 2.74 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded to four equivalent Sr and eight Cu atoms to form distorted SnSr4Cu8 cuboctahedra that share corners with four equivalent SnSr4Cu8 cuboctahedra, corners with six CuSr2Cu7Sn3 cuboctahedra, faces with eight CuSr2Cu7Sn3 cuboctahedra, and faces with eight equivalent SnSr4Cu8 cuboctahedra. In the second Sn site, Sn is bonded in a 10-coordinate geometry to six equivalent Sr and four Cu atoms.