ErSI crystallizes in the hexagonal P-6m2 space group. Er(1) is bonded in a trigonal planar geometry to three equivalent S(1) and six equivalent I(1) atoms. S(1) is bonded in a trigonal planar geometry to three equivalent Er(1) atoms. I(1) is bonded to six equivalent Er(1) atoms to form a mixture of distorted edge, face, and corner-sharing IEr6 pentagonal pyramids.
ErSI crystallizes in the hexagonal P-6m2 space group. Er(1) is bonded in a trigonal planar geometry to three equivalent S(1) and six equivalent I(1) atoms. All Er(1)-S(1) bond lengths are 2.59 Å. All Er(1)-I(1) bond lengths are 3.64 Å. S(1) is bonded in a trigonal planar geometry to three equivalent Er(1) atoms. I(1) is bonded to six equivalent Er(1) atoms to form a mixture of distorted edge, face, and corner-sharing IEr6 pentagonal pyramids.