Yb2PbS4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one S(2), two equivalent S(4), and three equivalent S(1) atoms to form YbS6 octahedra that share corners with four equivalent Pb(1)S5 square pyramids, edges with four equivalent Yb(1)S6 octahedra, and edges with three equivalent Pb(1)S5 square pyramids. In the second Yb site, Yb(2) is bonded in a 7-coordinate geometry to one S(1), one S(4), two equivalent S(2), and three equivalent S(3) atoms. Pb(1) is bonded to one S(4), two equivalent S(1), and two equivalent S(2) atoms to form distorted PbS5 square pyramids that share corners with four equivalent Yb(1)S6 octahedra, edges with three equivalent Yb(1)S6 octahedra, and edges with two equivalent Pb(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 9-61°. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Yb(2), three equivalent Yb(1), and two equivalent Pb(1) atoms to form SYb4Pb2 octahedra that share corners with three equivalent S(4)Yb3Pb trigonal pyramids, edges with four equivalent S(1)Yb4Pb2 octahedra, and edges with three equivalent S(4)Yb3Pb trigonal pyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Yb(1), two equivalent Yb(2), and two equivalent Pb(1) atoms. In the third S site, S(3) is bonded in a distorted pentagonal planar geometry to three equivalent Yb(2) and two equivalent S(3) atoms. In the fourth S site, S(4) is bonded to one Yb(2), two equivalent Yb(1), and one Pb(1) atom to form distorted SYb3Pb trigonal pyramids that share corners with three equivalent S(1)Yb4Pb2 octahedra, corners with two equivalent S(4)Yb3Pb trigonal pyramids, and edges with three equivalent S(1)Yb4Pb2 octahedra. The corner-sharing octahedral tilt angles range from 5-21°.
Yb2PbS4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one S(2), two equivalent S(4), and three equivalent S(1) atoms to form YbS6 octahedra that share corners with four equivalent Pb(1)S5 square pyramids, edges with four equivalent Yb(1)S6 octahedra, and edges with three equivalent Pb(1)S5 square pyramids. The Yb(1)-S(2) bond length is 2.70 Å. Both Yb(1)-S(4) bond lengths are 2.70 Å. There is one shorter (2.85 Å) and two longer (2.88 Å) Yb(1)-S(1) bond lengths. In the second Yb site, Yb(2) is bonded in a 7-coordinate geometry to one S(1), one S(4), two equivalent S(2), and three equivalent S(3) atoms. The Yb(2)-S(1) bond length is 2.87 Å. The Yb(2)-S(4) bond length is 2.75 Å. Both Yb(2)-S(2) bond lengths are 2.75 Å. There is one shorter (2.78 Å) and two longer (3.10 Å) Yb(2)-S(3) bond lengths. Pb(1) is bonded to one S(4), two equivalent S(1), and two equivalent S(2) atoms to form distorted PbS5 square pyramids that share corners with four equivalent Yb(1)S6 octahedra, edges with three equivalent Yb(1)S6 octahedra, and edges with two equivalent Pb(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 9-61°. The Pb(1)-S(4) bond length is 2.62 Å. Both Pb(1)-S(1) bond lengths are 2.98 Å. Both Pb(1)-S(2) bond lengths are 2.90 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Yb(2), three equivalent Yb(1), and two equivalent Pb(1) atoms to form SYb4Pb2 octahedra that share corners with three equivalent S(4)Yb3Pb trigonal pyramids, edges with four equivalent S(1)Yb4Pb2 octahedra, and edges with three equivalent S(4)Yb3Pb trigonal pyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Yb(1), two equivalent Yb(2), and two equivalent Pb(1) atoms. In the third S site, S(3) is bonded in a distorted pentagonal planar geometry to three equivalent Yb(2) and two equivalent S(3) atoms. Both S(3)-S(3) bond lengths are 2.25 Å. In the fourth S site, S(4) is bonded to one Yb(2), two equivalent Yb(1), and one Pb(1) atom to form distorted SYb3Pb trigonal pyramids that share corners with three equivalent S(1)Yb4Pb2 octahedra, corners with two equivalent S(4)Yb3Pb trigonal pyramids, and edges with three equivalent S(1)Yb4Pb2 octahedra. The corner-sharing octahedral tilt angles range from 5-21°.