Materials Data on NaCaH3 by Materials Project

Abstract

NaCaH3 is Ilmenite-like structured and crystallizes in the trigonal R3c space group. The structure is three-dimensional. Na1+ is bonded to six equivalent H1- atoms to form distorted NaH6 pentagonal pyramids that share corners with three equivalent CaH6 octahedra, corners with six equivalent NaH6 pentagonal pyramids, edges with three equivalent CaH6 octahedra, and a faceface with one CaH6 octahedra. The corner-sharing octahedral tilt angles are 66°. There are three shorter (2.29 Å) and three longer (2.44 Å) Na–H bond lengths. Ca2+ is bonded to six equivalent H1- atoms to form CaH6 octahedra that share corners with six equivalent CaH6 octahedra, corners with three equivalent NaH6 pentagonal pyramids, edges with three equivalent NaH6 pentagonal pyramids, and a faceface with one NaH6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 44°. There are three shorter (2.27 Å) and three longer (2.31 Å) Ca–H bond lengths. H1- is bonded to two equivalent Na1+ and two equivalent Ca2+ atoms to form a mixture of distorted edge and corner-sharing HNa2Ca2 trigonal pyramids.