Materials Data on Ca19Ag8N7 by Materials Project

Abstract

Ca19Ag8N7 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are three inequivalent Ca sites. In the first Ca site, Ca is bonded in a distorted L-shaped geometry to four equivalent Ag and two equivalent N atoms. All Ca–Ag bond lengths are 3.47 Å. Both Ca–N bond lengths are 2.41 Å. In the second Ca site, Ca is bonded in an octahedral geometry to six equivalent N atoms. All Ca–N bond lengths are 2.54 Å. In the third Ca site, Ca is bonded in a linear geometry to four equivalent Ag and two N atoms. All Ca–Ag bond lengths are 3.64 Å. There are one shorter (2.35 Å) and one longer (2.41 Å) Ca–N bond lengths. Ag is bonded to nine Ca and three equivalent Ag atoms to form AgCa9Ag3 cuboctahedra that share corners with three equivalent AgCa9Ag3 cuboctahedra, corners with six equivalent NCa6 octahedra, edges with three equivalent AgCa9Ag3 cuboctahedra, faces with six equivalent AgCa9Ag3 cuboctahedra, and faces with four NCa6 octahedra. The corner-sharing octahedral tilt angles are 48°. All Ag–Ag bond lengths are 3.05 Å. There are two inequivalent N sites. In the first N site, N is bonded to six equivalent Ca atoms to form NCa6 octahedra that share corners with six equivalent NCa6 octahedra and faces with eight equivalent AgCa9Ag3 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. In the second N site, N is bonded to six Ca atoms to form NCa6 octahedra that share corners with eight equivalent AgCa9Ag3 cuboctahedra, corners with two NCa6 octahedra, edges with four equivalent NCa6 octahedra, and faces with four equivalent AgCa9Ag3 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.