Materials Data on KMg6Si by Materials Project
KMg6Si crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. K is bonded in a 12-coordinate geometry to eight Mg and two equivalent Si atoms. There are a spread of K–Mg bond distances ranging from 3.42–3.66 Å. Both K–Si bond lengths are 3.46 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted single-bond geometry to one K, six Mg, and one Si atom. There are a spread of Mg–Mg bond distances ranging from 3.06–3.24 Å. The Mg–Si bond length is 2.75 Å. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent K, five Mg, and two equivalent Si atoms. There are a spread of Mg–Mg bond distances ranging from 3.00–3.25 Å. Both Mg–Si bond lengths are 2.88 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent K and eight Mg atoms. Both Mg–Mg bond lengths are 3.16 Å. In the fourth Mg site, Mg is bonded in a distorted hexagonal planar geometry to six Mg atoms. Si is bonded in a 8-coordinate geometry to two equivalent K and six Mg atoms.