Er2PbS4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one S(3), two equivalent S(1), and three equivalent S(4) atoms to form a mixture of corner and edge-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. In the second Er site, Er(2) is bonded to one S(1), two equivalent S(3), and three equivalent S(2) atoms to form a mixture of corner and edge-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. Pb(1) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(1), two equivalent S(2), and two equivalent S(4) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one Er(2), two equivalent Er(1), and two equivalent Pb(1) atoms. In the second S site, S(2) is bonded to three equivalent Er(2) and two equivalent Pb(1) atoms to form distorted SEr3Pb2 square pyramids that share corners with two equivalent S(3)Er3Pb trigonal pyramids, edges with four equivalent S(2)Er3Pb2 square pyramids, and edges with three equivalent S(3)Er3Pb trigonal pyramids. In the third S site, S(3) is bonded to one Er(1), two equivalent Er(2), and one Pb(1) atom to form distorted SEr3Pb trigonal pyramids that share corners with two equivalent S(2)Er3Pb2 square pyramids, corners with two equivalent S(3)Er3Pb trigonal pyramids, and edges with three equivalent S(2)Er3Pb2 square pyramids. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to three equivalent Er(1) and two equivalent Pb(1) atoms.
Er2PbS4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one S(3), two equivalent S(1), and three equivalent S(4) atoms to form a mixture of corner and edge-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. The Er(1)-S(3) bond length is 2.71 Å. Both Er(1)-S(1) bond lengths are 2.77 Å. There is one shorter (2.67 Å) and two longer (2.69 Å) Er(1)-S(4) bond lengths. In the second Er site, Er(2) is bonded to one S(1), two equivalent S(3), and three equivalent S(2) atoms to form a mixture of corner and edge-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles range from 48-62°. The Er(2)-S(1) bond length is 2.71 Å. Both Er(2)-S(3) bond lengths are 2.66 Å. All Er(2)-S(2) bond lengths are 2.73 Å. Pb(1) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(1), two equivalent S(2), and two equivalent S(4) atoms. The Pb(1)-S(3) bond length is 3.00 Å. Both Pb(1)-S(1) bond lengths are 3.10 Å. Both Pb(1)-S(2) bond lengths are 3.01 Å. Both Pb(1)-S(4) bond lengths are 3.24 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 3-coordinate geometry to one Er(2), two equivalent Er(1), and two equivalent Pb(1) atoms. In the second S site, S(2) is bonded to three equivalent Er(2) and two equivalent Pb(1) atoms to form distorted SEr3Pb2 square pyramids that share corners with two equivalent S(3)Er3Pb trigonal pyramids, edges with four equivalent S(2)Er3Pb2 square pyramids, and edges with three equivalent S(3)Er3Pb trigonal pyramids. In the third S site, S(3) is bonded to one Er(1), two equivalent Er(2), and one Pb(1) atom to form distorted SEr3Pb trigonal pyramids that share corners with two equivalent S(2)Er3Pb2 square pyramids, corners with two equivalent S(3)Er3Pb trigonal pyramids, and edges with three equivalent S(2)Er3Pb2 square pyramids. In the fourth S site, S(4) is bonded in a 3-coordinate geometry to three equivalent Er(1) and two equivalent Pb(1) atoms.