Materials Data on KNpAgS3 by Materials Project
KNpAgS3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of K–S bond distances ranging from 3.24–3.58 Å. Np4+ is bonded to six S2- atoms to form NpS6 octahedra that share corners with two equivalent NpS6 octahedra, edges with two equivalent NpS6 octahedra, and edges with four equivalent AgS4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are four shorter (2.73 Å) and two longer (2.75 Å) Np–S bond lengths. Ag1+ is bonded to four S2- atoms to form AgS4 tetrahedra that share corners with two equivalent AgS4 tetrahedra and edges with four equivalent NpS6 octahedra. There are two shorter (2.47 Å) and two longer (2.56 Å) Ag–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to three equivalent K1+, two equivalent Np4+, and one Ag1+ atom. In the second S2- site, S2- is bonded to two equivalent K1+, two equivalent Np4+, and two equivalent Ag1+ atoms to form a mixture of distorted edge and corner-sharing SK2Np2Ag2 octahedra. The corner-sharing octahedral tilt angles are 0°.