Materials Data on K2MgH4 by Materials Project

Abstract

K2MgH4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a distorted q6 geometry to nine H1- atoms. There are four shorter (2.82 Å) and five longer (2.86 Å) K–H bond lengths. Mg2+ is bonded to six H1- atoms to form corner-sharing MgH6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.01 Å) and four longer (2.02 Å) Mg–H bond lengths. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded to five equivalent K1+ and one Mg2+ atom to form distorted HK5Mg octahedra that share corners with seventeen HK5Mg octahedra, edges with eight equivalent HK5Mg octahedra, and faces with four equivalent HK4Mg2 octahedra. The corner-sharing octahedra tilt angles range from 0–59°. In the second H1- site, H1- is bonded to four equivalent K1+ and two equivalent Mg2+ atoms to form distorted HK4Mg2 octahedra that share corners with fourteen HK5Mg octahedra, edges with two equivalent HK4Mg2 octahedra, and faces with eight HK5Mg octahedra. The corner-sharing octahedra tilt angles range from 0–59°.