ErPS crystallizes in the orthorhombic Pnma space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 9-coordinate geometry to four equivalent P(1), two equivalent S(2), and three equivalent S(1) atoms. In the second Er site, Er(2) is bonded in a 9-coordinate geometry to four equivalent P(1), two equivalent S(1), and three equivalent S(2) atoms. P(1) is bonded in a 6-coordinate geometry to two equivalent Er(1), two equivalent Er(2), and two equivalent P(1) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Er(2) and three equivalent Er(1) atoms to form a mixture of distorted corner and edge-sharing SEr5 trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Er(1) and three equivalent Er(2) atoms to form a mixture of distorted corner and edge-sharing SEr5 trigonal bipyramids.
ErPS crystallizes in the orthorhombic Pnma space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 9-coordinate geometry to four equivalent P(1), two equivalent S(2), and three equivalent S(1) atoms. There are two shorter (3.06 Å) and two longer (3.08 Å) Er(1)-P(1) bond lengths. Both Er(1)-S(2) bond lengths are 2.75 Å. There are a spread of Er(1)-S(1) bond distances ranging from 2.77-2.86 Å. In the second Er site, Er(2) is bonded in a 9-coordinate geometry to four equivalent P(1), two equivalent S(1), and three equivalent S(2) atoms. There are two shorter (2.88 Å) and two longer (3.08 Å) Er(2)-P(1) bond lengths. Both Er(2)-S(1) bond lengths are 2.73 Å. There are a spread of Er(2)-S(2) bond distances ranging from 2.71-2.80 Å. P(1) is bonded in a 6-coordinate geometry to two equivalent Er(1), two equivalent Er(2), and two equivalent P(1) atoms. Both P(1)-P(1) bond lengths are 2.24 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Er(2) and three equivalent Er(1) atoms to form a mixture of distorted corner and edge-sharing SEr5 trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Er(1) and three equivalent Er(2) atoms to form a mixture of distorted corner and edge-sharing SEr5 trigonal bipyramids.