Ba2Ru7O18 crystallizes in the triclinic P-1 space group. Ba(1) is bonded to one O(2), one O(3), one O(5), one O(7), two equivalent O(1), two equivalent O(4), two equivalent O(6), and two equivalent O(9) atoms to form distorted BaO12 cuboctahedra that share  a cornercorner with one Ru(4)O6 octahedra, corners with two equivalent Ru(1)O6 octahedra, corners with two equivalent Ru(2)O6 octahedra, corners with two equivalent Ru(3)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra,  an edgeedge with one Ru(2)O6 octahedra,  an edgeedge with one Ru(3)O6 octahedra,  an edgeedge with one Ru(4)O6 octahedra, edges with two equivalent Ru(1)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ru(2)O6 octahedra, and faces with two equivalent Ru(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-52°. There are four inequivalent Ru sites. In the first Ru site, Ru(1) is bonded to one O(2), one O(4), one O(5), one O(8), and two equivalent O(3) atoms to form RuO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Ru(3)O6 octahedra, corners with three equivalent Ru(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra,  an edgeedge with one Ru(1)O6 octahedra, and edges with two equivalent Ru(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. In the second Ru site, Ru(2) is bonded to one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form RuO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ru(1)O6 octahedra, corners with three equivalent Ru(4)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra,  an edgeedge with one Ru(3)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 39-52°. In the third Ru site, Ru(3) is bonded to two equivalent O(1), two equivalent O(8), and two equivalent O(9) atoms to form RuO6 octahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Ru(1)O6 octahedra, corners with two equivalent Ru(4)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, and edges with two equivalent Ru(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the fourth Ru site, Ru(4) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form RuO6 octahedra that share  a cornercorner with one Ba(1)O12 cuboctahedra,  a cornercorner with one Ru(3)O6 octahedra, corners with three equivalent Ru(2)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra, edges with two equivalent Ru(1)O6 octahedra, and faces with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 39-51°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Ru(3), and one Ru(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Ru(1), one Ru(2), and one Ru(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Ru(4), and two equivalent Ru(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Ba(1), one Ru(1), and one Ru(4) atom to form a mixture of distorted edge and corner-sharing OBa2Ru2 tetrahedra. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ba(1), one Ru(1), and one Ru(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Ru(2), and one Ru(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ru(2), and one Ru(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ru(1), one Ru(2), and one Ru(3) atom. In the ninth O site, O(9) is bonded to two equivalent Ba(1), one Ru(2), and one Ru(3) atom to form a mixture of distorted edge and corner-sharing OBa2Ru2 tetrahedra.
Ba2Ru7O18 crystallizes in the triclinic P-1 space group. Ba(1) is bonded to one O(2), one O(3), one O(5), one O(7), two equivalent O(1), two equivalent O(4), two equivalent O(6), and two equivalent O(9) atoms to form distorted BaO12 cuboctahedra that share  a cornercorner with one Ru(4)O6 octahedra, corners with two equivalent Ru(1)O6 octahedra, corners with two equivalent Ru(2)O6 octahedra, corners with two equivalent Ru(3)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra,  an edgeedge with one Ru(2)O6 octahedra,  an edgeedge with one Ru(3)O6 octahedra,  an edgeedge with one Ru(4)O6 octahedra, edges with two equivalent Ru(1)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ru(2)O6 octahedra, and faces with two equivalent Ru(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-52°. The Ba(1)-O(2) bond length is 2.95 Å. The Ba(1)-O(3) bond length is 3.01 Å. The Ba(1)-O(5) bond length is 2.89 Å. The Ba(1)-O(7) bond length is 3.14 Å. There is one shorter (2.84 Å) and one longer (2.99 Å) Ba(1)-O(1) bond length. There is one shorter (2.71 Å) and one longer (2.94 Å) Ba(1)-O(4) bond length. There is one shorter (2.86 Å) and one longer (2.90 Å) Ba(1)-O(6) bond length. There is one shorter (2.77 Å) and one longer (2.86 Å) Ba(1)-O(9) bond length. There are four inequivalent Ru sites. In the first Ru site, Ru(1) is bonded to one O(2), one O(4), one O(5), one O(8), and two equivalent O(3) atoms to form RuO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra,  a cornercorner with one Ru(3)O6 octahedra, corners with three equivalent Ru(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra,  an edgeedge with one Ru(1)O6 octahedra, and edges with two equivalent Ru(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. The Ru(1)-O(2) bond length is 2.01 Å. The Ru(1)-O(4) bond length is 1.93 Å. The Ru(1)-O(5) bond length is 1.90 Å. The Ru(1)-O(8) bond length is 1.95 Å. Both Ru(1)-O(3) bond lengths are 2.04 Å. In the second Ru site, Ru(2) is bonded to one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form RuO6 octahedra that share corners with two equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ru(1)O6 octahedra, corners with three equivalent Ru(4)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra,  an edgeedge with one Ru(3)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 39-52°. The Ru(2)-O(2) bond length is 2.04 Å. The Ru(2)-O(5) bond length is 1.89 Å. The Ru(2)-O(6) bond length is 1.91 Å. The Ru(2)-O(7) bond length is 1.87 Å. The Ru(2)-O(8) bond length is 2.09 Å. The Ru(2)-O(9) bond length is 1.93 Å. In the third Ru site, Ru(3) is bonded to two equivalent O(1), two equivalent O(8), and two equivalent O(9) atoms to form RuO6 octahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Ru(1)O6 octahedra, corners with two equivalent Ru(4)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, and edges with two equivalent Ru(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. Both Ru(3)-O(1) bond lengths are 1.92 Å. Both Ru(3)-O(8) bond lengths are 2.01 Å. Both Ru(3)-O(9) bond lengths are 1.99 Å. In the fourth Ru site, Ru(4) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form RuO6 octahedra that share  a cornercorner with one Ba(1)O12 cuboctahedra,  a cornercorner with one Ru(3)O6 octahedra, corners with three equivalent Ru(2)O6 octahedra,  an edgeedge with one Ba(1)O12 cuboctahedra, edges with two equivalent Ru(1)O6 octahedra, and faces with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 39-51°. The Ru(4)-O(1) bond length is 1.91 Å. The Ru(4)-O(2) bond length is 2.04 Å. The Ru(4)-O(3) bond length is 2.03 Å. The Ru(4)-O(4) bond length is 1.99 Å. The Ru(4)-O(6) bond length is 1.93 Å. The Ru(4)-O(7) bond length is 1.85 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Ru(3), and one Ru(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Ru(1), one Ru(2), and one Ru(4) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Ru(4), and two equivalent Ru(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Ba(1), one Ru(1), and one Ru(4) atom to form a mixture of distorted edge and corner-sharing OBa2Ru2 tetrahedra. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Ba(1), one Ru(1), and one Ru(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ba(1), one Ru(2), and one Ru(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Ru(2), and one Ru(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ru(1), one Ru(2), and one Ru(3) atom. In the ninth O site, O(9) is bonded to two equivalent Ba(1), one Ru(2), and one Ru(3) atom to form a mixture of distorted edge and corner-sharing OBa2Ru2 tetrahedra.