La5Cu6O4S7 crystallizes in the orthorhombic Ima2 space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 2-coordinate geometry to one S(2), one S(3), two equivalent S(4), two equivalent S(5), and two equivalent O(2) atoms. In the second La site, La(2) is bonded in a 4-coordinate geometry to two equivalent S(1), two equivalent S(3), and four equivalent O(1) atoms. In the third La site, La(3) is bonded in a 4-coordinate geometry to one S(1), one S(4), two equivalent S(3), two equivalent O(1), and two equivalent O(2) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form a mixture of corner and edge-sharing CuS4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form a mixture of corner and edge-sharing CuS4 tetrahedra. In the third Cu site, Cu(3) is bonded to two equivalent S(3) and two equivalent S(4) atoms to form a mixture of distorted corner and edge-sharing CuS4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to two equivalent S(3) and two equivalent S(4) atoms to form a mixture of distorted corner and edge-sharing CuS4 tetrahedra. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 8-coordinate geometry to two equivalent La(2), two equivalent La(3), two equivalent Cu(1), and two equivalent Cu(2) atoms. In the second S site, S(2) is bonded to two equivalent La(1), two equivalent Cu(1), and two equivalent Cu(2) atoms to form distorted SLa2Cu4 pentagonal pyramids that share corners with four equivalent O(2)La4 tetrahedra. In the third S site, S(3) is bonded in a 8-coordinate geometry to one La(1), one La(2), two equivalent La(3), one Cu(1), one Cu(2), one Cu(3), and one Cu(4) atom. In the fourth S site, S(4) is bonded in a 7-coordinate geometry to one La(3), two equivalent La(1), one Cu(1), one Cu(2), one Cu(3), and one Cu(4) atom. In the fifth S site, S(5) is bonded in a distorted square co-planar geometry to four equivalent La(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(2) and two equivalent La(3) atoms to form a mixture of corner and edge-sharing OLa4 tetrahedra. In the second O site, O(2) is bonded to two equivalent La(1) and two equivalent La(3) atoms to form OLa4 tetrahedra that share corners with two equivalent S(2)La2Cu4 pentagonal pyramids, corners with two equivalent O(1)La4 tetrahedra,  an edgeedge with one O(1)La4 tetrahedra, and edges with two equivalent O(2)La4 tetrahedra.
La5Cu6O4S7 crystallizes in the orthorhombic Ima2 space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 2-coordinate geometry to one S(2), one S(3), two equivalent S(4), two equivalent S(5), and two equivalent O(2) atoms. The La(1)-S(2) bond length is 2.97 Å. The La(1)-S(3) bond length is 3.15 Å. There is one shorter (3.21 Å) and one longer (3.24 Å) La(1)-S(4) bond length. There is one shorter (2.99 Å) and one longer (3.07 Å) La(1)-S(5) bond length. There is one shorter (2.34 Å) and one longer (2.35 Å) La(1)-O(2) bond length. In the second La site, La(2) is bonded in a 4-coordinate geometry to two equivalent S(1), two equivalent S(3), and four equivalent O(1) atoms. Both La(2)-S(1) bond lengths are 3.16 Å. Both La(2)-S(3) bond lengths are 3.20 Å. All La(2)-O(1) bond lengths are 2.38 Å. In the third La site, La(3) is bonded in a 4-coordinate geometry to one S(1), one S(4), two equivalent S(3), two equivalent O(1), and two equivalent O(2) atoms. The La(3)-S(1) bond length is 3.21 Å. The La(3)-S(4) bond length is 3.05 Å. Both La(3)-S(3) bond lengths are 3.22 Å. There is one shorter (2.34 Å) and one longer (2.35 Å) La(3)-O(1) bond length. There is one shorter (2.43 Å) and one longer (2.44 Å) La(3)-O(2) bond length. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form a mixture of corner and edge-sharing CuS4 tetrahedra. The Cu(1)-S(1) bond length is 2.39 Å. The Cu(1)-S(2) bond length is 2.32 Å. The Cu(1)-S(3) bond length is 2.46 Å. The Cu(1)-S(4) bond length is 2.37 Å. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form a mixture of corner and edge-sharing CuS4 tetrahedra. The Cu(2)-S(1) bond length is 2.39 Å. The Cu(2)-S(2) bond length is 2.32 Å. The Cu(2)-S(3) bond length is 2.46 Å. The Cu(2)-S(4) bond length is 2.36 Å. In the third Cu site, Cu(3) is bonded to two equivalent S(3) and two equivalent S(4) atoms to form a mixture of distorted corner and edge-sharing CuS4 tetrahedra. Both Cu(3)-S(3) bond lengths are 2.40 Å. Both Cu(3)-S(4) bond lengths are 2.39 Å. In the fourth Cu site, Cu(4) is bonded to two equivalent S(3) and two equivalent S(4) atoms to form a mixture of distorted corner and edge-sharing CuS4 tetrahedra. Both Cu(4)-S(3) bond lengths are 2.40 Å. Both Cu(4)-S(4) bond lengths are 2.39 Å. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 8-coordinate geometry to two equivalent La(2), two equivalent La(3), two equivalent Cu(1), and two equivalent Cu(2) atoms. In the second S site, S(2) is bonded to two equivalent La(1), two equivalent Cu(1), and two equivalent Cu(2) atoms to form distorted SLa2Cu4 pentagonal pyramids that share corners with four equivalent O(2)La4 tetrahedra. In the third S site, S(3) is bonded in a 8-coordinate geometry to one La(1), one La(2), two equivalent La(3), one Cu(1), one Cu(2), one Cu(3), and one Cu(4) atom. In the fourth S site, S(4) is bonded in a 7-coordinate geometry to one La(3), two equivalent La(1), one Cu(1), one Cu(2), one Cu(3), and one Cu(4) atom. In the fifth S site, S(5) is bonded in a distorted square co-planar geometry to four equivalent La(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(2) and two equivalent La(3) atoms to form a mixture of corner and edge-sharing OLa4 tetrahedra. In the second O site, O(2) is bonded to two equivalent La(1) and two equivalent La(3) atoms to form OLa4 tetrahedra that share corners with two equivalent S(2)La2Cu4 pentagonal pyramids, corners with two equivalent O(1)La4 tetrahedra,  an edgeedge with one O(1)La4 tetrahedra, and edges with two equivalent O(2)La4 tetrahedra.