KErS2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. K(1) is bonded to six equivalent S(1) atoms to form distorted KS6 octahedra that share corners with six equivalent Er(1)S6 octahedra, edges with six equivalent K(1)S6 octahedra, and edges with six equivalent Er(1)S6 octahedra. The corner-sharing octahedral tilt angles are 11°. Er(1) is bonded to six equivalent S(1) atoms to form ErS6 octahedra that share corners with six equivalent K(1)S6 octahedra, edges with six equivalent K(1)S6 octahedra, and edges with six equivalent Er(1)S6 octahedra. The corner-sharing octahedral tilt angles are 11°. S(1) is bonded to three equivalent K(1) and three equivalent Er(1) atoms to form a mixture of corner and edge-sharing SK3Er3 octahedra. The corner-sharing octahedra are not tilted.
KErS2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. K(1) is bonded to six equivalent S(1) atoms to form distorted KS6 octahedra that share corners with six equivalent Er(1)S6 octahedra, edges with six equivalent K(1)S6 octahedra, and edges with six equivalent Er(1)S6 octahedra. The corner-sharing octahedral tilt angles are 11°. All K(1)-S(1) bond lengths are 3.18 Å. Er(1) is bonded to six equivalent S(1) atoms to form ErS6 octahedra that share corners with six equivalent K(1)S6 octahedra, edges with six equivalent K(1)S6 octahedra, and edges with six equivalent Er(1)S6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Er(1)-S(1) bond lengths are 2.73 Å. S(1) is bonded to three equivalent K(1) and three equivalent Er(1) atoms to form a mixture of corner and edge-sharing SK3Er3 octahedra. The corner-sharing octahedra are not tilted.