Materials Data on KMg6Sn by Materials Project
KMg6Sn crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. K is bonded to ten Mg and two equivalent Sn atoms to form a mixture of corner and face-sharing KMg10Sn2 cuboctahedra. There are a spread of K–Mg bond distances ranging from 3.34–3.52 Å. Both K–Sn bond lengths are 3.33 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent K, eight Mg, and one Sn atom. There are a spread of Mg–Mg bond distances ranging from 3.20–3.37 Å. The Mg–Sn bond length is 3.35 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent K, three Mg, and two equivalent Sn atoms. The Mg–Mg bond length is 3.26 Å. Both Mg–Sn bond lengths are 3.18 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to six Mg and two equivalent Sn atoms. Both Mg–Mg bond lengths are 3.33 Å. Both Mg–Sn bond lengths are 3.38 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent K and eight Mg atoms. Sn is bonded in a 10-coordinate geometry to two equivalent K and eight Mg atoms.