Materials Data on NaLaS2 by Materials Project

Abstract

NaLaS2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Na1+ is bonded to six S2- atoms to form NaS6 octahedra that share corners with six equivalent NaS6 octahedra, edges with four equivalent NaS6 octahedra, and edges with eight equivalent LaS6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.83 Å) and four longer (2.97 Å) Na–S bond lengths. La3+ is bonded to six S2- atoms to form LaS6 octahedra that share corners with six equivalent LaS6 octahedra, edges with four equivalent LaS6 octahedra, and edges with eight equivalent NaS6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.83 Å) and four longer (2.97 Å) La–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Na1+ and four equivalent La3+ atoms to form a mixture of corner and edge-sharing SNa2La4 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second S2- site, S2- is bonded to four equivalent Na1+ and two equivalent La3+ atoms to form SNa4La2 octahedra that share corners with six equivalent SNa4La2 octahedra and edges with twelve SNa2La4 octahedra. The corner-sharing octahedral tilt angles are 0°.