La9Ni6O19 crystallizes in the monoclinic C2/m space group. There are five inequivalent La sites. In the first La site, La(1) is bonded in a distorted q6 geometry to one O(7), two equivalent O(4), two equivalent O(5), and four equivalent O(6) atoms. In the second La site, La(2) is bonded in a distorted q6 geometry to two equivalent O(7), four equivalent O(4), and four equivalent O(5) atoms. In the third La site, La(3) is bonded in a 9-coordinate geometry to one O(2), one O(3), two equivalent O(4), two equivalent O(6), and three equivalent O(1) atoms. In the fourth La site, La(4) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. In the fifth La site, La(5) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), two equivalent O(4), and two equivalent O(6) atoms to form distorted corner-sharing NiO5 square pyramids. The corner-sharing octahedral tilt angles are 2°. In the second Ni site, Ni(2) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra and corners with two equivalent Ni(1)O5 square pyramids. The corner-sharing octahedra are not tilted. In the third Ni site, Ni(3) is bonded in a distorted rectangular see-saw-like geometry to one O(3), two equivalent O(5), and two equivalent O(6) atoms. There are seven inequivalent O sites. In the first O site, O(3) is bonded in a 6-coordinate geometry to one La(3), two equivalent La(4), two equivalent La(5), and one Ni(3) atom. In the second O site, O(4) is bonded to one La(1), one La(2), one La(3), one La(5), one Ni(1), and one Ni(2) atom to form a mixture of distorted corner, edge, and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. In the third O site, O(5) is bonded to one La(1), one La(2), one La(4), one La(5), one Ni(2), and one Ni(3) atom to form a mixture of distorted corner, edge, and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. In the fourth O site, O(6) is bonded to one La(3), one La(4), two equivalent La(1), one Ni(1), and one Ni(3) atom to form a mixture of distorted corner, edge, and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 2-73°. In the fifth O site, O(7) is bonded to two equivalent La(1), two equivalent La(2), and two equivalent Ni(2) atoms to form a mixture of distorted corner and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the sixth O site, O(1) is bonded in a 6-coordinate geometry to one La(4), one La(5), three equivalent La(3), and one Ni(1) atom. In the seventh O site, O(2) is bonded in a 6-coordinate geometry to one La(3), two equivalent La(4), two equivalent La(5), and one Ni(2) atom.
La9Ni6O19 crystallizes in the monoclinic C2/m space group. There are five inequivalent La sites. In the first La site, La(1) is bonded in a distorted q6 geometry to one O(7), two equivalent O(4), two equivalent O(5), and four equivalent O(6) atoms. The La(1)-O(7) bond length is 2.59 Å. Both La(1)-O(4) bond lengths are 2.66 Å. Both La(1)-O(5) bond lengths are 2.59 Å. There are two shorter (2.58 Å) and two longer (2.65 Å) La(1)-O(6) bond lengths. In the second La site, La(2) is bonded in a distorted q6 geometry to two equivalent O(7), four equivalent O(4), and four equivalent O(5) atoms. Both La(2)-O(7) bond lengths are 2.76 Å. All La(2)-O(4) bond lengths are 2.73 Å. All La(2)-O(5) bond lengths are 2.69 Å. In the third La site, La(3) is bonded in a 9-coordinate geometry to one O(2), one O(3), two equivalent O(4), two equivalent O(6), and three equivalent O(1) atoms. The La(3)-O(2) bond length is 3.05 Å. The La(3)-O(3) bond length is 2.55 Å. Both La(3)-O(4) bond lengths are 2.65 Å. Both La(3)-O(6) bond lengths are 2.72 Å. There is one shorter (2.27 Å) and two longer (2.84 Å) La(3)-O(1) bond lengths. In the fourth La site, La(4) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. The La(4)-O(1) bond length is 2.46 Å. There is one shorter (2.32 Å) and one longer (2.71 Å) La(4)-O(2) bond length. Both La(4)-O(3) bond lengths are 2.83 Å. Both La(4)-O(5) bond lengths are 2.65 Å. Both La(4)-O(6) bond lengths are 2.83 Å. In the fifth La site, La(5) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. The La(5)-O(1) bond length is 3.24 Å. Both La(5)-O(2) bond lengths are 2.82 Å. There is one shorter (2.28 Å) and one longer (3.01 Å) La(5)-O(3) bond length. Both La(5)-O(4) bond lengths are 2.56 Å. Both La(5)-O(5) bond lengths are 2.54 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), two equivalent O(4), and two equivalent O(6) atoms to form distorted corner-sharing NiO5 square pyramids. The corner-sharing octahedral tilt angles are 2°. The Ni(1)-O(1) bond length is 2.49 Å. Both Ni(1)-O(4) bond lengths are 1.92 Å. Both Ni(1)-O(6) bond lengths are 1.91 Å. In the second Ni site, Ni(2) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra and corners with two equivalent Ni(1)O5 square pyramids. The corner-sharing octahedra are not tilted. The Ni(2)-O(2) bond length is 2.09 Å. The Ni(2)-O(7) bond length is 1.97 Å. Both Ni(2)-O(4) bond lengths are 2.03 Å. Both Ni(2)-O(5) bond lengths are 2.02 Å. In the third Ni site, Ni(3) is bonded in a distorted rectangular see-saw-like geometry to one O(3), two equivalent O(5), and two equivalent O(6) atoms. The Ni(3)-O(3) bond length is 2.58 Å. Both Ni(3)-O(5) bond lengths are 1.93 Å. Both Ni(3)-O(6) bond lengths are 1.94 Å. There are seven inequivalent O sites. In the first O site, O(3) is bonded in a 6-coordinate geometry to one La(3), two equivalent La(4), two equivalent La(5), and one Ni(3) atom. In the second O site, O(4) is bonded to one La(1), one La(2), one La(3), one La(5), one Ni(1), and one Ni(2) atom to form a mixture of distorted corner, edge, and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. In the third O site, O(5) is bonded to one La(1), one La(2), one La(4), one La(5), one Ni(2), and one Ni(3) atom to form a mixture of distorted corner, edge, and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. In the fourth O site, O(6) is bonded to one La(3), one La(4), two equivalent La(1), one Ni(1), and one Ni(3) atom to form a mixture of distorted corner, edge, and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 2-73°. In the fifth O site, O(7) is bonded to two equivalent La(1), two equivalent La(2), and two equivalent Ni(2) atoms to form a mixture of distorted corner and face-sharing OLa4Ni2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the sixth O site, O(1) is bonded in a 6-coordinate geometry to one La(4), one La(5), three equivalent La(3), and one Ni(1) atom. In the seventh O site, O(2) is bonded in a 6-coordinate geometry to one La(3), two equivalent La(4), two equivalent La(5), and one Ni(2) atom.