Materials Data on KNa4Cl5 by Materials Project

Abstract

KNa4Cl5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded to six Cl1- atoms to form KCl6 octahedra that share corners with two equivalent NaCl6 octahedra, corners with four equivalent KCl6 octahedra, edges with four equivalent KCl6 octahedra, and edges with eight equivalent NaCl6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.95 Å) and two longer (3.06 Å) K–Cl bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Cl1- atoms to form NaCl6 octahedra that share corners with six NaCl6 octahedra, edges with four equivalent KCl6 octahedra, and edges with eight NaCl6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Na–Cl bond distances ranging from 2.83–2.99 Å. In the second Na1+ site, Na1+ is bonded to six Cl1- atoms to form NaCl6 octahedra that share a cornercorner with one KCl6 octahedra, corners with five NaCl6 octahedra, and edges with twelve NaCl6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Na–Cl bond distances ranging from 2.79–2.95 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to one K1+ and five Na1+ atoms to form a mixture of edge and corner-sharing ClKNa5 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the second Cl1- site, Cl1- is bonded to four equivalent K1+ and two equivalent Na1+ atoms to form ClK4Na2 octahedra that share corners with six ClK4Na2 octahedra and edges with twelve ClKNa5 octahedra. The corner-sharing octahedral tilt angles are 0°. Both Cl–Na bond lengths are 2.99 Å. In the third Cl1- site, Cl1- is bonded to six Na1+ atoms to form ClNa6 octahedra that share corners with six ClK4Na2 octahedra and edges with twelve ClKNa5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth Cl1- site, Cl1- is bonded to four equivalent K1+ and two equivalent Na1+ atoms to form a mixture of edge and corner-sharing ClK4Na2 octahedra. The corner-sharing octahedral tilt angles are 0°. All Cl–K bond lengths are 2.95 Å.