Sr2UCu2S5 crystallizes in the monoclinic C2/m space group. Sr(1) is bonded in a 7-coordinate geometry to two equivalent S(1), two equivalent S(3), and three equivalent S(2) atoms. U(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form US6 octahedra that share edges with two equivalent U(1)S6 octahedra and edges with four equivalent Cu(1)S4 tetrahedra. Cu(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with three equivalent Cu(1)S4 tetrahedra and edges with two equivalent U(1)S6 octahedra. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one U(1), and two equivalent Cu(1) atoms. In the second S site, S(2) is bonded to three equivalent Sr(1), two equivalent U(1), and one Cu(1) atom to form distorted SSr3U2Cu octahedra that share corners with two equivalent S(2)Sr3U2Cu octahedra, corners with four equivalent S(3)Sr4Cu2 octahedra, edges with five equivalent S(2)Sr3U2Cu octahedra, and  a faceface with one S(3)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third S site, S(3) is bonded to four equivalent Sr(1) and two equivalent Cu(1) atoms to form SSr4Cu2 octahedra that share corners with eight equivalent S(2)Sr3U2Cu octahedra, edges with two equivalent S(3)Sr4Cu2 octahedra, and faces with two equivalent S(2)Sr3U2Cu octahedra. The corner-sharing octahedral tilt angles range from 45-60°.
Sr2UCu2S5 crystallizes in the monoclinic C2/m space group. Sr(1) is bonded in a 7-coordinate geometry to two equivalent S(1), two equivalent S(3), and three equivalent S(2) atoms. Both Sr(1)-S(1) bond lengths are 3.05 Å. Both Sr(1)-S(3) bond lengths are 2.98 Å. There are two shorter (3.24 Å) and one longer (3.32 Å) Sr(1)-S(2) bond length. U(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form US6 octahedra that share edges with two equivalent U(1)S6 octahedra and edges with four equivalent Cu(1)S4 tetrahedra. Both U(1)-S(1) bond lengths are 2.70 Å. All U(1)-S(2) bond lengths are 2.76 Å. Cu(1) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with three equivalent Cu(1)S4 tetrahedra and edges with two equivalent U(1)S6 octahedra. The Cu(1)-S(2) bond length is 2.37 Å. The Cu(1)-S(3) bond length is 2.33 Å. Both Cu(1)-S(1) bond lengths are 2.36 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to two equivalent Sr(1), one U(1), and two equivalent Cu(1) atoms. In the second S site, S(2) is bonded to three equivalent Sr(1), two equivalent U(1), and one Cu(1) atom to form distorted SSr3U2Cu octahedra that share corners with two equivalent S(2)Sr3U2Cu octahedra, corners with four equivalent S(3)Sr4Cu2 octahedra, edges with five equivalent S(2)Sr3U2Cu octahedra, and  a faceface with one S(3)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third S site, S(3) is bonded to four equivalent Sr(1) and two equivalent Cu(1) atoms to form SSr4Cu2 octahedra that share corners with eight equivalent S(2)Sr3U2Cu octahedra, edges with two equivalent S(3)Sr4Cu2 octahedra, and faces with two equivalent S(2)Sr3U2Cu octahedra. The corner-sharing octahedral tilt angles range from 45-60°.