Materials Data on LiCa3As2H by Materials Project

Abstract

LiCa3As2H crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Li1+ is bonded to three As3- and one H1- atom to form distorted LiAs3H trigonal pyramids that share corners with three equivalent CaAs5H octahedra, corners with two equivalent LiAs3H trigonal pyramids, and edges with three equivalent CaAs5H octahedra. The corner-sharing octahedra tilt angles range from 2–37°. There are two shorter (2.55 Å) and one longer (2.58 Å) Li–As bond lengths. The Li–H bond length is 2.06 Å. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 1-coordinate geometry to five As3- and one H1- atom. There are a spread of Ca–As bond distances ranging from 3.03–3.26 Å. The Ca–H bond length is 2.34 Å. In the second Ca2+ site, Ca2+ is bonded to five As3- and one H1- atom to form distorted CaAs5H octahedra that share corners with three equivalent LiAs3H trigonal pyramids, edges with four equivalent CaAs5H octahedra, and edges with three equivalent LiAs3H trigonal pyramids. There are a spread of Ca–As bond distances ranging from 3.09–3.12 Å. The Ca–H bond length is 2.40 Å. In the third Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to four As3- and two equivalent H1- atoms. There are a spread of Ca–As bond distances ranging from 2.98–3.14 Å. Both Ca–H bond lengths are 2.41 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 2-coordinate geometry to two equivalent Li1+ and seven Ca2+ atoms. In the second As3- site, As3- is bonded in a 1-coordinate geometry to one Li1+ and seven Ca2+ atoms. H1- is bonded to one Li1+ and four Ca2+ atoms to form corner-sharing HLiCa4 trigonal bipyramids.