Materials Data on K2MgCl4 by Materials Project

Abstract

K2MgCl4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine Cl1- atoms. There are a spread of K–Cl bond distances ranging from 3.12–3.55 Å. Mg2+ is bonded to six Cl1- atoms to form corner-sharing MgCl6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.50 Å) and two longer (2.51 Å) Mg–Cl bond lengths. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to four equivalent K1+ and two equivalent Mg2+ atoms to form a mixture of distorted edge, face, and corner-sharing ClK4Mg2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°. In the second Cl1- site, Cl1- is bonded to five equivalent K1+ and one Mg2+ atom to form distorted ClK5Mg octahedra that share corners with seventeen ClK4Mg2 octahedra, edges with eight equivalent ClK5Mg octahedra, and faces with four equivalent ClK4Mg2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°.