TbEu4S5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. Tb(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form TbS6 octahedra that share corners with two equivalent Eu(2)S6 octahedra; corners with four equivalent Tb(1)S6 octahedra; edges with four equivalent Tb(1)S6 octahedra; and edges with eight Eu(1,1)S6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form EuS6 octahedra that share  a cornercorner with one Eu(2)S6 octahedra; corners with five Eu(1,1)S6 octahedra; edges with four equivalent Tb(1)S6 octahedra; edges with four equivalent Eu(1)S6 octahedra; and edges with four equivalent Eu(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second Eu site, Eu(2) is bonded to one S(1) and five equivalent S(3) atoms to form EuS6 octahedra that share  a cornercorner with one Tb(1)S6 octahedra,  a cornercorner with one Eu(1)S6 octahedra, corners with four equivalent Eu(2)S6 octahedra, edges with four equivalent Eu(1)S6 octahedra, and edges with eight equivalent Eu(2)S6 octahedra. The corner-sharing octahedra are not tilted. In the third Eu site, Eu(1) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form EuS6 octahedra that share  a cornercorner with one Eu(2)S6 octahedra; corners with five Eu(1,1)S6 octahedra; edges with four equivalent Tb(1)S6 octahedra; edges with four equivalent Eu(1)S6 octahedra; and edges with four equivalent Eu(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Tb(1), one Eu(2), and four equivalent Eu(1) atoms to form STbEu5 octahedra that share  a cornercorner with one S(3)Eu6 octahedra, corners with five equivalent S(1)TbEu5 octahedra, edges with four equivalent S(3)Eu6 octahedra, edges with four equivalent S(2)Tb4Eu2 octahedra, and edges with four equivalent S(1)TbEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second S site, S(2) is bonded to four equivalent Tb(1) and two Eu(1,1) atoms to form STb4Eu2 octahedra that share corners with two equivalent S(3)Eu6 octahedra, corners with four equivalent S(2)Tb4Eu2 octahedra, edges with four equivalent S(2)Tb4Eu2 octahedra, and edges with eight equivalent S(1)TbEu5 octahedra. The corner-sharing octahedra are not tilted. In the third S site, S(3) is bonded to one Eu(1) and five equivalent Eu(2) atoms to form SEu6 octahedra that share  a cornercorner with one S(2)Tb4Eu2 octahedra,  a cornercorner with one S(1)TbEu5 octahedra, corners with four equivalent S(3)Eu6 octahedra, edges with four equivalent S(1)TbEu5 octahedra, and edges with eight equivalent S(3)Eu6 octahedra. The corner-sharing octahedra are not tilted.
TbEu4S5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. Tb(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form TbS6 octahedra that share corners with two equivalent Eu(2)S6 octahedra; corners with four equivalent Tb(1)S6 octahedra; edges with four equivalent Tb(1)S6 octahedra; and edges with eight Eu(1,1)S6 octahedra. The corner-sharing octahedra are not tilted. Both Tb(1)-S(1) bond lengths are 2.79 Å. All Tb(1)-S(2) bond lengths are 2.89 Å. There are three inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form EuS6 octahedra that share  a cornercorner with one Eu(2)S6 octahedra; corners with five Eu(1,1)S6 octahedra; edges with four equivalent Tb(1)S6 octahedra; edges with four equivalent Eu(1)S6 octahedra; and edges with four equivalent Eu(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Eu(1)-S(2) bond length is 2.87 Å. The Eu(1)-S(3) bond length is 2.90 Å. All Eu(1)-S(1) bond lengths are 2.89 Å. In the second Eu site, Eu(2) is bonded to one S(1) and five equivalent S(3) atoms to form EuS6 octahedra that share  a cornercorner with one Tb(1)S6 octahedra,  a cornercorner with one Eu(1)S6 octahedra, corners with four equivalent Eu(2)S6 octahedra, edges with four equivalent Eu(1)S6 octahedra, and edges with eight equivalent Eu(2)S6 octahedra. The corner-sharing octahedra are not tilted. The Eu(2)-S(1) bond length is 2.98 Å. There are four shorter (2.89 Å) and one longer (2.91 Å) Eu(2)-S(3) bond length. In the third Eu site, Eu(1) is bonded to one S(2), one S(3), and four equivalent S(1) atoms to form EuS6 octahedra that share  a cornercorner with one Eu(2)S6 octahedra; corners with five Eu(1,1)S6 octahedra; edges with four equivalent Tb(1)S6 octahedra; edges with four equivalent Eu(1)S6 octahedra; and edges with four equivalent Eu(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Eu(1)-S(2) bond length is 2.87 Å. The Eu(1)-S(3) bond length is 2.90 Å. All Eu(1)-S(1) bond lengths are 2.89 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Tb(1), one Eu(2), and four equivalent Eu(1) atoms to form STbEu5 octahedra that share  a cornercorner with one S(3)Eu6 octahedra, corners with five equivalent S(1)TbEu5 octahedra, edges with four equivalent S(3)Eu6 octahedra, edges with four equivalent S(2)Tb4Eu2 octahedra, and edges with four equivalent S(1)TbEu5 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second S site, S(2) is bonded to four equivalent Tb(1) and two Eu(1,1) atoms to form STb4Eu2 octahedra that share corners with two equivalent S(3)Eu6 octahedra, corners with four equivalent S(2)Tb4Eu2 octahedra, edges with four equivalent S(2)Tb4Eu2 octahedra, and edges with eight equivalent S(1)TbEu5 octahedra. The corner-sharing octahedra are not tilted. In the third S site, S(3) is bonded to one Eu(1) and five equivalent Eu(2) atoms to form SEu6 octahedra that share  a cornercorner with one S(2)Tb4Eu2 octahedra,  a cornercorner with one S(1)TbEu5 octahedra, corners with four equivalent S(3)Eu6 octahedra, edges with four equivalent S(1)TbEu5 octahedra, and edges with eight equivalent S(3)Eu6 octahedra. The corner-sharing octahedra are not tilted.