La6Cu6O17 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one O(2), one O(5), one O(6), two equivalent O(1), and two equivalent O(7) atoms. In the second La site, La(2) is bonded in a distorted body-centered cubic geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(1), and two equivalent O(7) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to one O(4), one O(5), and two equivalent O(7) atoms. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(3) atoms. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(4) and two equivalent O(6) atoms. In the fourth Cu site, Cu(4) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. There are seven inequivalent O sites. In the first O site, O(7) is bonded to one La(1), two equivalent La(2), and one Cu(1) atom to form OLa3Cu tetrahedra that share  a cornercorner with one O(2)La3Cu tetrahedra, corners with three equivalent O(6)La3Cu tetrahedra, corners with four equivalent O(7)La3Cu tetrahedra, corners with two equivalent O(3)La2Cu3 trigonal bipyramids, corners with two equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(2)La3Cu tetrahedra, and edges with two equivalent O(1)La3Cu trigonal pyramids. In the second O site, O(1) is bonded to one La(1), two equivalent La(2), and one Cu(4) atom to form distorted OLa3Cu trigonal pyramids that share  a cornercorner with one O(6)La3Cu tetrahedra, corners with two equivalent O(7)La3Cu tetrahedra, corners with three equivalent O(2)La3Cu tetrahedra, corners with four equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(6)La3Cu tetrahedra, edges with two equivalent O(7)La3Cu tetrahedra, and edges with two equivalent O(3)La2Cu3 trigonal bipyramids. In the third O site, O(2) is bonded to one La(1), two equivalent La(2), and one Cu(2) atom to form distorted OLa3Cu tetrahedra that share  a cornercorner with one O(2)La3Cu tetrahedra,  a cornercorner with one O(6)La3Cu tetrahedra, corners with two equivalent O(7)La3Cu tetrahedra, corners with six equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(6)La3Cu tetrahedra, edges with two equivalent O(7)La3Cu tetrahedra, and edges with two equivalent O(3)La2Cu3 trigonal bipyramids. In the fourth O site, O(3) is bonded to two equivalent La(2), one Cu(2), and two equivalent Cu(4) atoms to form distorted OLa2Cu3 trigonal bipyramids that share corners with two equivalent O(6)La3Cu tetrahedra, corners with four equivalent O(7)La3Cu tetrahedra, corners with three equivalent O(3)La2Cu3 trigonal bipyramids, edges with two equivalent O(2)La3Cu tetrahedra, and edges with four equivalent O(1)La3Cu trigonal pyramids. In the fifth O site, O(4) is bonded in a square co-planar geometry to two equivalent La(2), one Cu(1), and one Cu(3) atom. In the sixth O site, O(5) is bonded in a distorted square co-planar geometry to two equivalent La(1) and two equivalent Cu(1) atoms. In the seventh O site, O(6) is bonded to one La(1), two equivalent La(2), and one Cu(3) atom to form distorted OLa3Cu tetrahedra that share  a cornercorner with one O(2)La3Cu tetrahedra,  a cornercorner with one O(6)La3Cu tetrahedra, corners with six equivalent O(7)La3Cu tetrahedra, corners with two equivalent O(3)La2Cu3 trigonal bipyramids, corners with two equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(2)La3Cu tetrahedra, and edges with two equivalent O(1)La3Cu trigonal pyramids.
La6Cu6O17 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one O(2), one O(5), one O(6), two equivalent O(1), and two equivalent O(7) atoms. The La(1)-O(2) bond length is 2.46 Å. The La(1)-O(5) bond length is 2.74 Å. The La(1)-O(6) bond length is 2.41 Å. Both La(1)-O(1) bond lengths are 2.54 Å. Both La(1)-O(7) bond lengths are 2.38 Å. In the second La site, La(2) is bonded in a distorted body-centered cubic geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(1), and two equivalent O(7) atoms. The La(2)-O(2) bond length is 2.53 Å. The La(2)-O(3) bond length is 2.72 Å. The La(2)-O(4) bond length is 2.55 Å. The La(2)-O(6) bond length is 2.42 Å. There is one shorter (2.51 Å) and one longer (2.58 Å) La(2)-O(1) bond length. There is one shorter (2.40 Å) and one longer (2.43 Å) La(2)-O(7) bond length. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to one O(4), one O(5), and two equivalent O(7) atoms. The Cu(1)-O(4) bond length is 1.97 Å. The Cu(1)-O(5) bond length is 1.92 Å. Both Cu(1)-O(7) bond lengths are 1.85 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Cu(2)-O(2) bond lengths are 1.86 Å. Both Cu(2)-O(3) bond lengths are 1.94 Å. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(4) and two equivalent O(6) atoms. Both Cu(3)-O(4) bond lengths are 1.98 Å. Both Cu(3)-O(6) bond lengths are 1.85 Å. In the fourth Cu site, Cu(4) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Cu(4)-O(1) bond lengths are 1.87 Å. Both Cu(4)-O(3) bond lengths are 1.96 Å. There are seven inequivalent O sites. In the first O site, O(7) is bonded to one La(1), two equivalent La(2), and one Cu(1) atom to form OLa3Cu tetrahedra that share  a cornercorner with one O(2)La3Cu tetrahedra, corners with three equivalent O(6)La3Cu tetrahedra, corners with four equivalent O(7)La3Cu tetrahedra, corners with two equivalent O(3)La2Cu3 trigonal bipyramids, corners with two equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(2)La3Cu tetrahedra, and edges with two equivalent O(1)La3Cu trigonal pyramids. In the second O site, O(1) is bonded to one La(1), two equivalent La(2), and one Cu(4) atom to form distorted OLa3Cu trigonal pyramids that share  a cornercorner with one O(6)La3Cu tetrahedra, corners with two equivalent O(7)La3Cu tetrahedra, corners with three equivalent O(2)La3Cu tetrahedra, corners with four equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(6)La3Cu tetrahedra, edges with two equivalent O(7)La3Cu tetrahedra, and edges with two equivalent O(3)La2Cu3 trigonal bipyramids. In the third O site, O(2) is bonded to one La(1), two equivalent La(2), and one Cu(2) atom to form distorted OLa3Cu tetrahedra that share  a cornercorner with one O(2)La3Cu tetrahedra,  a cornercorner with one O(6)La3Cu tetrahedra, corners with two equivalent O(7)La3Cu tetrahedra, corners with six equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(6)La3Cu tetrahedra, edges with two equivalent O(7)La3Cu tetrahedra, and edges with two equivalent O(3)La2Cu3 trigonal bipyramids. In the fourth O site, O(3) is bonded to two equivalent La(2), one Cu(2), and two equivalent Cu(4) atoms to form distorted OLa2Cu3 trigonal bipyramids that share corners with two equivalent O(6)La3Cu tetrahedra, corners with four equivalent O(7)La3Cu tetrahedra, corners with three equivalent O(3)La2Cu3 trigonal bipyramids, edges with two equivalent O(2)La3Cu tetrahedra, and edges with four equivalent O(1)La3Cu trigonal pyramids. In the fifth O site, O(4) is bonded in a square co-planar geometry to two equivalent La(2), one Cu(1), and one Cu(3) atom. In the sixth O site, O(5) is bonded in a distorted square co-planar geometry to two equivalent La(1) and two equivalent Cu(1) atoms. In the seventh O site, O(6) is bonded to one La(1), two equivalent La(2), and one Cu(3) atom to form distorted OLa3Cu tetrahedra that share  a cornercorner with one O(2)La3Cu tetrahedra,  a cornercorner with one O(6)La3Cu tetrahedra, corners with six equivalent O(7)La3Cu tetrahedra, corners with two equivalent O(3)La2Cu3 trigonal bipyramids, corners with two equivalent O(1)La3Cu trigonal pyramids,  an edgeedge with one O(2)La3Cu tetrahedra, and edges with two equivalent O(1)La3Cu trigonal pyramids.