Ba3Pt2O7 crystallizes in the monoclinic Cc space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(2), one O(4), one O(6), one O(7), and one O(9) atom. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(1), one O(12), one O(13), one O(14), one O(2), one O(3), one O(5), one O(6), one O(7), and one O(9) atom. In the third Ba site, Ba(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(8), and one O(9) atom. In the fourth Ba site, Ba(4) is bonded in a 9-coordinate geometry to one O(10), one O(13), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the fifth Ba site, Ba(5) is bonded in a 9-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(5), two equivalent O(10), and two equivalent O(8) atoms. In the sixth Ba site, Ba(6) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(9), and two equivalent O(14) atoms. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to one O(10), one O(11), one O(2), one O(3), one O(7), and one O(9) atom to form face-sharing PtO6 octahedra. In the second Pt site, Pt(2) is bonded in a trigonal bipyramidal geometry to one O(1), one O(13), one O(14), one O(5), and one O(8) atom. In the third Pt site, Pt(3) is bonded in a distorted square co-planar geometry to one O(11), one O(12), one O(6), and one O(7) atom. In the fourth Pt site, Pt(4) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(9) atom to form face-sharing PtO6 octahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(6), and one Pt(2) atom. In the second O site, O(2) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Pt(1), and one Pt(4) atom to form distorted OBa4Pt2 octahedra that share corners with two equivalent O(9)Ba4Pt2 octahedra,  a cornercorner with one O(4)Ba4Pt trigonal bipyramid, corners with two equivalent O(8)Ba4Pt trigonal bipyramids,  a faceface with one O(10)Ba4Pt2 octahedra,  a faceface with one O(9)Ba4Pt2 octahedra, and  a faceface with one O(4)Ba4Pt trigonal bipyramid. The corner-sharing octahedral tilt angles range from 39-42°. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(5), and one Pt(1) atom. In the fourth O site, O(4) is bonded to one Ba(1), one Ba(3), one Ba(4), one Ba(5), and one Pt(4) atom to form distorted OBa4Pt trigonal bipyramids that share  a cornercorner with one O(10)Ba4Pt2 octahedra,  a cornercorner with one O(2)Ba4Pt2 octahedra,  a cornercorner with one O(9)Ba4Pt2 octahedra,  an edgeedge with one O(9)Ba4Pt2 octahedra, edges with two equivalent O(8)Ba4Pt trigonal bipyramids,  a faceface with one O(10)Ba4Pt2 octahedra, and  a faceface with one O(2)Ba4Pt2 octahedra. The corner-sharing octahedral tilt angles range from 13-62°. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(5), and one Pt(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Pt(3), and one Pt(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Pt(1), and one Pt(3) atom. In the eighth O site, O(8) is bonded to one Ba(3), one Ba(4), two equivalent Ba(5), and one Pt(2) atom to form distorted OBa4Pt trigonal bipyramids that share  a cornercorner with one O(9)Ba4Pt2 octahedra, corners with two equivalent O(10)Ba4Pt2 octahedra, corners with two equivalent O(2)Ba4Pt2 octahedra, corners with two equivalent O(8)Ba4Pt trigonal bipyramids, edges with two equivalent O(4)Ba4Pt trigonal bipyramids, and  a faceface with one O(10)Ba4Pt2 octahedra. The corner-sharing octahedral tilt angles range from 2-59°. In the ninth O site, O(9) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(6), one Pt(1), and one Pt(4) atom to form OBa4Pt2 octahedra that share corners with two equivalent O(2)Ba4Pt2 octahedra,  a cornercorner with one O(4)Ba4Pt trigonal bipyramid,  a cornercorner with one O(8)Ba4Pt trigonal bipyramid,  an edgeedge with one O(4)Ba4Pt trigonal bipyramid,  a faceface with one O(10)Ba4Pt2 octahedra, and  a faceface with one O(2)Ba4Pt2 octahedra. The corner-sharing octahedral tilt angles range from 39-42°. In the tenth O site, O(10) is bonded to one Ba(4), one Ba(6), two equivalent Ba(5), one Pt(1), and one Pt(4) atom to form distorted OBa4Pt2 octahedra that share corners with two equivalent O(10)Ba4Pt2 octahedra,  a cornercorner with one O(4)Ba4Pt trigonal bipyramid, corners with two equivalent O(8)Ba4Pt trigonal bipyramids,  a faceface with one O(2)Ba4Pt2 octahedra,  a faceface with one O(9)Ba4Pt2 octahedra,  a faceface with one O(4)Ba4Pt trigonal bipyramid, and  a faceface with one O(8)Ba4Pt trigonal bipyramid. The corner-sharing octahedral tilt angles are 43°. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(5), one Ba(6), one Pt(1), and one Pt(3) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(5), one Ba(6), one Pt(3), and one Pt(4) atom. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Ba(6), and one Pt(2) atom. In the fourteenth O site, O(14) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), two equivalent Ba(6), and one Pt(2) atom.
Ba3Pt2O7 crystallizes in the monoclinic Cc space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(2), one O(4), one O(6), one O(7), and one O(9) atom. The Ba(1)-O(1) bond length is 2.71 Å. The Ba(1)-O(11) bond length is 3.02 Å. The Ba(1)-O(13) bond length is 2.63 Å. The Ba(1)-O(14) bond length is 3.11 Å. The Ba(1)-O(2) bond length is 2.92 Å. The Ba(1)-O(4) bond length is 2.94 Å. The Ba(1)-O(6) bond length is 2.99 Å. The Ba(1)-O(7) bond length is 3.11 Å. The Ba(1)-O(9) bond length is 2.88 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(1), one O(12), one O(13), one O(14), one O(2), one O(3), one O(5), one O(6), one O(7), and one O(9) atom. The Ba(2)-O(1) bond length is 2.70 Å. The Ba(2)-O(12) bond length is 3.12 Å. The Ba(2)-O(13) bond length is 3.04 Å. The Ba(2)-O(14) bond length is 2.81 Å. The Ba(2)-O(2) bond length is 2.94 Å. The Ba(2)-O(3) bond length is 3.17 Å. The Ba(2)-O(5) bond length is 2.74 Å. The Ba(2)-O(6) bond length is 3.22 Å. The Ba(2)-O(7) bond length is 2.85 Å. The Ba(2)-O(9) bond length is 2.92 Å. In the third Ba site, Ba(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(8), and one O(9) atom. The Ba(3)-O(1) bond length is 2.78 Å. The Ba(3)-O(2) bond length is 3.03 Å. The Ba(3)-O(3) bond length is 2.62 Å. The Ba(3)-O(4) bond length is 2.60 Å. The Ba(3)-O(5) bond length is 2.64 Å. The Ba(3)-O(8) bond length is 2.92 Å. The Ba(3)-O(9) bond length is 2.90 Å. In the fourth Ba site, Ba(4) is bonded in a 9-coordinate geometry to one O(10), one O(13), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Ba(4)-O(10) bond length is 2.89 Å. The Ba(4)-O(13) bond length is 2.70 Å. The Ba(4)-O(2) bond length is 2.92 Å. The Ba(4)-O(3) bond length is 2.88 Å. The Ba(4)-O(4) bond length is 2.79 Å. The Ba(4)-O(5) bond length is 2.72 Å. The Ba(4)-O(6) bond length is 2.78 Å. The Ba(4)-O(7) bond length is 2.75 Å. The Ba(4)-O(8) bond length is 2.76 Å. In the fifth Ba site, Ba(5) is bonded in a 9-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(5), two equivalent O(10), and two equivalent O(8) atoms. The Ba(5)-O(11) bond length is 3.03 Å. The Ba(5)-O(12) bond length is 3.03 Å. The Ba(5)-O(3) bond length is 2.82 Å. The Ba(5)-O(4) bond length is 2.92 Å. The Ba(5)-O(5) bond length is 3.07 Å. There is one shorter (2.83 Å) and one longer (3.01 Å) Ba(5)-O(10) bond length. There is one shorter (2.69 Å) and one longer (2.78 Å) Ba(5)-O(8) bond length. In the sixth Ba site, Ba(6) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(9), and two equivalent O(14) atoms. The Ba(6)-O(1) bond length is 3.01 Å. The Ba(6)-O(10) bond length is 2.99 Å. The Ba(6)-O(11) bond length is 2.70 Å. The Ba(6)-O(12) bond length is 2.82 Å. The Ba(6)-O(13) bond length is 2.95 Å. The Ba(6)-O(9) bond length is 2.87 Å. There is one shorter (2.60 Å) and one longer (2.64 Å) Ba(6)-O(14) bond length. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to one O(10), one O(11), one O(2), one O(3), one O(7), and one O(9) atom to form face-sharing PtO6 octahedra. The Pt(1)-O(10) bond length is 2.05 Å. The Pt(1)-O(11) bond length is 2.04 Å. The Pt(1)-O(2) bond length is 2.06 Å. The Pt(1)-O(3) bond length is 2.01 Å. The Pt(1)-O(7) bond length is 2.04 Å. The Pt(1)-O(9) bond length is 2.17 Å. In the second Pt site, Pt(2) is bonded in a trigonal bipyramidal geometry to one O(1), one O(13), one O(14), one O(5), and one O(8) atom. The Pt(2)-O(1) bond length is 1.99 Å. The Pt(2)-O(13) bond length is 1.95 Å. The Pt(2)-O(14) bond length is 2.01 Å. The Pt(2)-O(5) bond length is 1.98 Å. The Pt(2)-O(8) bond length is 2.02 Å. In the third Pt site, Pt(3) is bonded in a distorted square co-planar geometry to one O(11), one O(12), one O(6), and one O(7) atom. The Pt(3)-O(11) bond length is 2.05 Å. The Pt(3)-O(12) bond length is 2.02 Å. The Pt(3)-O(6) bond length is 2.06 Å. The Pt(3)-O(7) bond length is 2.02 Å. In the fourth Pt site, Pt(4) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(9) atom to form face-sharing PtO6 octahedra. The Pt(4)-O(10) bond length is 2.07 Å. The Pt(4)-O(12) bond length is 2.03 Å. The Pt(4)-O(2) bond length is 2.05 Å. The Pt(4)-O(4) bond length is 2.00 Å. The Pt(4)-O(6) bond length is 2.04 Å. The Pt(4)-O(9) bond length is 2.18 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Ba(6), and one Pt(2) atom. In the second O site, O(2) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(4), one Pt(1), and one Pt(4) atom to form distorted OBa4Pt2 octahedra that share corners with two equivalent O(9)Ba4Pt2 octahedra,  a cornercorner with one O(4)Ba4Pt trigonal bipyramid, corners with two equivalent O(8)Ba4Pt trigonal bipyramids,  a faceface with one O(10)Ba4Pt2 octahedra,  a faceface with one O(9)Ba4Pt2 octahedra, and  a faceface with one O(4)Ba4Pt trigonal bipyramid. The corner-sharing octahedral tilt angles range from 39-42°. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(5), and one Pt(1) atom. In the fourth O site, O(4) is bonded to one Ba(1), one Ba(3), one Ba(4), one Ba(5), and one Pt(4) atom to form distorted OBa4Pt trigonal bipyramids that share  a cornercorner with one O(10)Ba4Pt2 octahedra,  a cornercorner with one O(2)Ba4Pt2 octahedra,  a cornercorner with one O(9)Ba4Pt2 octahedra,  an edgeedge with one O(9)Ba4Pt2 octahedra, edges with two equivalent O(8)Ba4Pt trigonal bipyramids,  a faceface with one O(10)Ba4Pt2 octahedra, and  a faceface with one O(2)Ba4Pt2 octahedra. The corner-sharing octahedral tilt angles range from 13-62°. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ba(2), one Ba(3), one Ba(4), one Ba(5), and one Pt(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Pt(3), and one Pt(4) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Pt(1), and one Pt(3) atom. In the eighth O site, O(8) is bonded to one Ba(3), one Ba(4), two equivalent Ba(5), and one Pt(2) atom to form distorted OBa4Pt trigonal bipyramids that share  a cornercorner with one O(9)Ba4Pt2 octahedra, corners with two equivalent O(10)Ba4Pt2 octahedra, corners with two equivalent O(2)Ba4Pt2 octahedra, corners with two equivalent O(8)Ba4Pt trigonal bipyramids, edges with two equivalent O(4)Ba4Pt trigonal bipyramids, and  a faceface with one O(10)Ba4Pt2 octahedra. The corner-sharing octahedral tilt angles range from 2-59°. In the ninth O site, O(9) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(6), one Pt(1), and one Pt(4) atom to form OBa4Pt2 octahedra that share corners with two equivalent O(2)Ba4Pt2 octahedra,  a cornercorner with one O(4)Ba4Pt trigonal bipyramid,  a cornercorner with one O(8)Ba4Pt trigonal bipyramid,  an edgeedge with one O(4)Ba4Pt trigonal bipyramid,  a faceface with one O(10)Ba4Pt2 octahedra, and  a faceface with one O(2)Ba4Pt2 octahedra. The corner-sharing octahedral tilt angles range from 39-42°. In the tenth O site, O(10) is bonded to one Ba(4), one Ba(6), two equivalent Ba(5), one Pt(1), and one Pt(4) atom to form distorted OBa4Pt2 octahedra that share corners with two equivalent O(10)Ba4Pt2 octahedra,  a cornercorner with one O(4)Ba4Pt trigonal bipyramid, corners with two equivalent O(8)Ba4Pt trigonal bipyramids,  a faceface with one O(2)Ba4Pt2 octahedra,  a faceface with one O(9)Ba4Pt2 octahedra,  a faceface with one O(4)Ba4Pt trigonal bipyramid, and  a faceface with one O(8)Ba4Pt trigonal bipyramid. The corner-sharing octahedral tilt angles are 43°. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(5), one Ba(6), one Pt(1), and one Pt(3) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(5), one Ba(6), one Pt(3), and one Pt(4) atom. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one Ba(4), one Ba(6), and one Pt(2) atom. In the fourteenth O site, O(14) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), two equivalent Ba(6), and one Pt(2) atom.