Materials Data on KNaH2 by Materials Project
KNaH2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. K1+ is bonded to six H1- atoms to form KH6 octahedra that share corners with six equivalent KH6 octahedra, edges with four equivalent KH6 octahedra, and edges with eight equivalent NaH6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.67 Å) and four longer (2.68 Å) K–H bond lengths. Na1+ is bonded to six H1- atoms to form NaH6 octahedra that share corners with six equivalent NaH6 octahedra, edges with four equivalent NaH6 octahedra, and edges with eight equivalent KH6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.67 Å) and four longer (2.68 Å) Na–H bond lengths. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded to four equivalent K1+ and two equivalent Na1+ atoms to form a mixture of edge and corner-sharing HK4Na2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second H1- site, H1- is bonded to two equivalent K1+ and four equivalent Na1+ atoms to form HK2Na4 octahedra that share corners with six equivalent HK2Na4 octahedra and edges with twelve HK4Na2 octahedra. The corner-sharing octahedral tilt angles are 0°.