Na5Ca2Ce3Ti8Nb2O30 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4mm space group. There are five inequivalent Na sites. In the first Na site, Na(1) is bonded to four equivalent O(1), four equivalent O(4), and four equivalent O(5) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(1)O12 cuboctahedra, corners with four equivalent Na(5)O12 cuboctahedra, corners with four equivalent Ce(1)O12 cuboctahedra,  a faceface with one Na(5)O12 cuboctahedra,  a faceface with one Ce(1)O12 cuboctahedra, faces with four equivalent Na(1)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. In the second Na site, Na(2) is bonded to four equivalent O(2), four equivalent O(7), and four equivalent O(9) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(2)O12 cuboctahedra, corners with four equivalent Ce(1)O12 cuboctahedra, corners with four equivalent Ce(2)O12 cuboctahedra,  a faceface with one Ce(1)O12 cuboctahedra,  a faceface with one Ce(2)O12 cuboctahedra, faces with four equivalent Na(2)O12 cuboctahedra, faces with four equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(4)O6 octahedra. In the third Na site, Na(3) is bonded to four equivalent O(10), four equivalent O(11), and four equivalent O(12) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(3)O12 cuboctahedra, corners with four equivalent Ce(2)O12 cuboctahedra, corners with four equivalent Ce(3)O12 cuboctahedra,  a faceface with one Ce(2)O12 cuboctahedra,  a faceface with one Ce(3)O12 cuboctahedra, faces with four equivalent Na(3)O12 cuboctahedra, faces with four equivalent Ti(3)O6 octahedra, and faces with four equivalent Ti(5)O6 octahedra. In the fourth Na site, Na(4) is bonded to four equivalent O(14), four equivalent O(15), and four equivalent O(3) atoms to form distorted NaO12 cuboctahedra that share corners with four equivalent Na(4)O12 cuboctahedra, corners with four equivalent Ca(1)O12 cuboctahedra, corners with four equivalent Ce(3)O12 cuboctahedra,  a faceface with one Ca(1)O12 cuboctahedra,  a faceface with one Ce(3)O12 cuboctahedra, faces with four equivalent Na(4)O12 cuboctahedra, faces with four equivalent Ti(6)O6 octahedra, and faces with four equivalent Ti(7)O6 octahedra. In the fifth Na site, Na(5) is bonded to four equivalent O(18), four equivalent O(20), and four equivalent O(4) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(1)O12 cuboctahedra, corners with four equivalent Na(5)O12 cuboctahedra, corners with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Na(1)O12 cuboctahedra,  a faceface with one Ca(2)O12 cuboctahedra, faces with four equivalent Na(5)O12 cuboctahedra, faces with four equivalent Nb(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to four equivalent O(15), four equivalent O(16), and four equivalent O(17) atoms to form distorted CaO12 cuboctahedra that share corners with four equivalent Na(4)O12 cuboctahedra, corners with four equivalent Ca(1)O12 cuboctahedra, corners with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Na(4)O12 cuboctahedra,  a faceface with one Ca(2)O12 cuboctahedra, faces with four equivalent Ca(1)O12 cuboctahedra, faces with four equivalent Ti(6)O6 octahedra, and faces with four equivalent Ti(8)O6 octahedra. In the second Ca site, Ca(2) is bonded to four equivalent O(16), four equivalent O(18), and four equivalent O(19) atoms to form CaO12 cuboctahedra that share corners with four equivalent Na(5)O12 cuboctahedra, corners with four equivalent Ca(1)O12 cuboctahedra, corners with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Na(5)O12 cuboctahedra,  a faceface with one Ca(1)O12 cuboctahedra, faces with four equivalent Ca(2)O12 cuboctahedra, faces with four equivalent Ti(8)O6 octahedra, and faces with four equivalent Nb(1)O6 octahedra. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(6) atoms to form CeO12 cuboctahedra that share corners with four equivalent Na(1)O12 cuboctahedra, corners with four equivalent Na(2)O12 cuboctahedra, corners with four equivalent Ce(1)O12 cuboctahedra,  a faceface with one Na(1)O12 cuboctahedra,  a faceface with one Na(2)O12 cuboctahedra, faces with four equivalent Ce(1)O12 cuboctahedra, faces with four equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. In the second Ce site, Ce(2) is bonded to four equivalent O(11), four equivalent O(8), and four equivalent O(9) atoms to form CeO12 cuboctahedra that share corners with four equivalent Na(2)O12 cuboctahedra, corners with four equivalent Na(3)O12 cuboctahedra, corners with four equivalent Ce(2)O12 cuboctahedra,  a faceface with one Na(2)O12 cuboctahedra,  a faceface with one Na(3)O12 cuboctahedra, faces with four equivalent Ce(2)O12 cuboctahedra, faces with four equivalent Ti(3)O6 octahedra, and faces with four equivalent Ti(4)O6 octahedra. In the third Ce site, Ce(3) is bonded to four equivalent O(12), four equivalent O(13), and four equivalent O(3) atoms to form CeO12 cuboctahedra that share corners with four equivalent Na(3)O12 cuboctahedra, corners with four equivalent Na(4)O12 cuboctahedra, corners with four equivalent Ce(3)O12 cuboctahedra,  a faceface with one Na(3)O12 cuboctahedra,  a faceface with one Na(4)O12 cuboctahedra, faces with four equivalent Ce(3)O12 cuboctahedra, faces with four equivalent Ti(5)O6 octahedra, and faces with four equivalent Ti(7)O6 octahedra. There are eight inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(6), one O(7), and four equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, faces with four equivalent Na(2)O12 cuboctahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the second Ti site, Ti(2) is bonded to one O(5), one O(6), and four equivalent O(1) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with four equivalent Na(1)O12 cuboctahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the third Ti site, Ti(3) is bonded to one O(10), one O(8), and four equivalent O(11) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(4)O6 octahedra,  a cornercorner with one Ti(5)O6 octahedra, corners with four equivalent Ti(3)O6 octahedra, faces with four equivalent Na(3)O12 cuboctahedra, and faces with four equivalent Ce(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the fourth Ti site, Ti(4) is bonded to one O(7), one O(8), and four equivalent O(9) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with four equivalent Ti(4)O6 octahedra, faces with four equivalent Na(2)O12 cuboctahedra, and faces with four equivalent Ce(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-13°. In the fifth Ti site, Ti(5) is bonded to one O(10), one O(13), and four equivalent O(12) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Ti(7)O6 octahedra, corners with four equivalent Ti(5)O6 octahedra, faces with four equivalent Na(3)O12 cuboctahedra, and faces with four equivalent Ce(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the sixth Ti site, Ti(6) is bonded to one O(14), one O(17), and four equivalent O(15) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(7)O6 octahedra,  a cornercorner with one Ti(8)O6 octahedra, corners with four equivalent Ti(6)O6 octahedra, faces with four equivalent Na(4)O12 cuboctahedra, and faces with four equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the seventh Ti site, Ti(7) is bonded to one O(13), one O(14), and four equivalent O(3) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(5)O6 octahedra,  a cornercorner with one Ti(6)O6 octahedra, corners with four equivalent Ti(7)O6 octahedra, faces with four equivalent Na(4)O12 cuboctahedra, and faces with four equivalent Ce(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-17°. In the eighth Ti site, Ti(8) is bonded to one O(17), one O(19), and four equivalent O(16) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(6)O6 octahedra,  a cornercorner with one Nb(1)O6 octahedra, corners with four equivalent Ti(8)O6 octahedra, faces with four equivalent Ca(1)O12 cuboctahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-8°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(19), one O(20), and four equivalent O(18) atoms to form NbO6 octahedra that share  a cornercorner with one Ti(8)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, faces with four equivalent Na(5)O12 cuboctahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second Nb site, Nb(2) is bonded to one O(20), one O(5), and four equivalent O(4) atoms to form NbO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, faces with four equivalent Na(1)O12 cuboctahedra, and faces with four equivalent Na(5)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1), two equivalent Ce(1), and two equivalent Ti(2) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Na(2), two equivalent Ce(1), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Na(4), two equivalent Ce(3), and two equivalent Ti(7) atoms. In the fourth O site, O(4) is bonded to two equivalent Na(1), two equivalent Na(5), and two equivalent Nb(2) atoms to form a mixture of distorted face, corner, and edge-sharing ONa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 1-58°. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Na(1), one Ti(2), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to four equivalent Ce(1), one Ti(1), and one Ti(2) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to four equivalent Na(2), one Ti(1), and one Ti(4) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to four equivalent Ce(2), one Ti(3), and one Ti(4) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Na(2), two equivalent Ce(2), and two equivalent Ti(4) atoms. In the tenth O site, O(10) is bonded in a distorted linear geometry to four equivalent Na(3), one Ti(3), and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to two equivalent Na(3), two equivalent Ce(2), and two equivalent Ti(3) atoms. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to two equivalent Na(3), two equivalent Ce(3), and two equivalent Ti(5) atoms. In the thirteenth O site, O(13) is bonded in a distorted linear geometry to four equivalent Ce(3), one Ti(5), and one Ti(7) atom. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to four equivalent Na(4), one Ti(6), and one Ti(7) atom. In the fifteenth O site, O(15) is bonded to two equivalent Na(4), two equivalent Ca(1), and two equivalent Ti(6) atoms to form a mixture of distorted face, corner, and edge-sharing ONa2Ca2Ti2 octahedra. The corner-sharing octahedral tilt angles are 9°. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Ti(8) atoms. In the seventeenth O site, O(17) is bonded in a distorted linear geometry to four equivalent Ca(1), one Ti(6), and one Ti(8) atom. In the eighteenth O site, O(18) is bonded in a distorted linear geometry to two equivalent Na(5), two equivalent Ca(2), and two equivalent Nb(1) atoms. In the nineteenth O site, O(19) is bonded in a distorted linear geometry to four equivalent Ca(2), one Ti(8), and one Nb(1) atom. In the twentieth O site, O(20) is bonded to four equivalent Na(5), one Nb(1), and one Nb(2) atom to form a mixture of distorted face, corner, and edge-sharing ONa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 3-58°.
Na5Ca2Ce3Ti8Nb2O30 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4mm space group. There are five inequivalent Na sites. In the first Na site, Na(1) is bonded to four equivalent O(1), four equivalent O(4), and four equivalent O(5) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(1)O12 cuboctahedra, corners with four equivalent Na(5)O12 cuboctahedra, corners with four equivalent Ce(1)O12 cuboctahedra,  a faceface with one Na(5)O12 cuboctahedra,  a faceface with one Ce(1)O12 cuboctahedra, faces with four equivalent Na(1)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. All Na(1)-O(1) bond lengths are 2.94 Å. All Na(1)-O(4) bond lengths are 2.77 Å. All Na(1)-O(5) bond lengths are 2.79 Å. In the second Na site, Na(2) is bonded to four equivalent O(2), four equivalent O(7), and four equivalent O(9) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(2)O12 cuboctahedra, corners with four equivalent Ce(1)O12 cuboctahedra, corners with four equivalent Ce(2)O12 cuboctahedra,  a faceface with one Ce(1)O12 cuboctahedra,  a faceface with one Ce(2)O12 cuboctahedra, faces with four equivalent Na(2)O12 cuboctahedra, faces with four equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(4)O6 octahedra. All Na(2)-O(2) bond lengths are 2.93 Å. All Na(2)-O(7) bond lengths are 2.79 Å. All Na(2)-O(9) bond lengths are 2.91 Å. In the third Na site, Na(3) is bonded to four equivalent O(10), four equivalent O(11), and four equivalent O(12) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(3)O12 cuboctahedra, corners with four equivalent Ce(2)O12 cuboctahedra, corners with four equivalent Ce(3)O12 cuboctahedra,  a faceface with one Ce(2)O12 cuboctahedra,  a faceface with one Ce(3)O12 cuboctahedra, faces with four equivalent Na(3)O12 cuboctahedra, faces with four equivalent Ti(3)O6 octahedra, and faces with four equivalent Ti(5)O6 octahedra. All Na(3)-O(10) bond lengths are 2.79 Å. All Na(3)-O(11) bond lengths are 2.95 Å. All Na(3)-O(12) bond lengths are 2.89 Å. In the fourth Na site, Na(4) is bonded to four equivalent O(14), four equivalent O(15), and four equivalent O(3) atoms to form distorted NaO12 cuboctahedra that share corners with four equivalent Na(4)O12 cuboctahedra, corners with four equivalent Ca(1)O12 cuboctahedra, corners with four equivalent Ce(3)O12 cuboctahedra,  a faceface with one Ca(1)O12 cuboctahedra,  a faceface with one Ce(3)O12 cuboctahedra, faces with four equivalent Na(4)O12 cuboctahedra, faces with four equivalent Ti(6)O6 octahedra, and faces with four equivalent Ti(7)O6 octahedra. All Na(4)-O(14) bond lengths are 2.79 Å. All Na(4)-O(15) bond lengths are 2.79 Å. All Na(4)-O(3) bond lengths are 3.03 Å. In the fifth Na site, Na(5) is bonded to four equivalent O(18), four equivalent O(20), and four equivalent O(4) atoms to form NaO12 cuboctahedra that share corners with four equivalent Na(1)O12 cuboctahedra, corners with four equivalent Na(5)O12 cuboctahedra, corners with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Na(1)O12 cuboctahedra,  a faceface with one Ca(2)O12 cuboctahedra, faces with four equivalent Na(5)O12 cuboctahedra, faces with four equivalent Nb(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. All Na(5)-O(18) bond lengths are 2.89 Å. All Na(5)-O(20) bond lengths are 2.79 Å. All Na(5)-O(4) bond lengths are 2.75 Å. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to four equivalent O(15), four equivalent O(16), and four equivalent O(17) atoms to form distorted CaO12 cuboctahedra that share corners with four equivalent Na(4)O12 cuboctahedra, corners with four equivalent Ca(1)O12 cuboctahedra, corners with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Na(4)O12 cuboctahedra,  a faceface with one Ca(2)O12 cuboctahedra, faces with four equivalent Ca(1)O12 cuboctahedra, faces with four equivalent Ti(6)O6 octahedra, and faces with four equivalent Ti(8)O6 octahedra. All Ca(1)-O(15) bond lengths are 2.54 Å. All Ca(1)-O(16) bond lengths are 2.99 Å. All Ca(1)-O(17) bond lengths are 2.80 Å. In the second Ca site, Ca(2) is bonded to four equivalent O(16), four equivalent O(18), and four equivalent O(19) atoms to form CaO12 cuboctahedra that share corners with four equivalent Na(5)O12 cuboctahedra, corners with four equivalent Ca(1)O12 cuboctahedra, corners with four equivalent Ca(2)O12 cuboctahedra,  a faceface with one Na(5)O12 cuboctahedra,  a faceface with one Ca(1)O12 cuboctahedra, faces with four equivalent Ca(2)O12 cuboctahedra, faces with four equivalent Ti(8)O6 octahedra, and faces with four equivalent Nb(1)O6 octahedra. All Ca(2)-O(16) bond lengths are 2.56 Å. All Ca(2)-O(18) bond lengths are 2.89 Å. All Ca(2)-O(19) bond lengths are 2.80 Å. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(6) atoms to form CeO12 cuboctahedra that share corners with four equivalent Na(1)O12 cuboctahedra, corners with four equivalent Na(2)O12 cuboctahedra, corners with four equivalent Ce(1)O12 cuboctahedra,  a faceface with one Na(1)O12 cuboctahedra,  a faceface with one Na(2)O12 cuboctahedra, faces with four equivalent Ce(1)O12 cuboctahedra, faces with four equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. All Ce(1)-O(1) bond lengths are 2.62 Å. All Ce(1)-O(2) bond lengths are 2.63 Å. All Ce(1)-O(6) bond lengths are 2.79 Å. In the second Ce site, Ce(2) is bonded to four equivalent O(11), four equivalent O(8), and four equivalent O(9) atoms to form CeO12 cuboctahedra that share corners with four equivalent Na(2)O12 cuboctahedra, corners with four equivalent Na(3)O12 cuboctahedra, corners with four equivalent Ce(2)O12 cuboctahedra,  a faceface with one Na(2)O12 cuboctahedra,  a faceface with one Na(3)O12 cuboctahedra, faces with four equivalent Ce(2)O12 cuboctahedra, faces with four equivalent Ti(3)O6 octahedra, and faces with four equivalent Ti(4)O6 octahedra. All Ce(2)-O(11) bond lengths are 2.62 Å. All Ce(2)-O(8) bond lengths are 2.79 Å. All Ce(2)-O(9) bond lengths are 2.65 Å. In the third Ce site, Ce(3) is bonded to four equivalent O(12), four equivalent O(13), and four equivalent O(3) atoms to form CeO12 cuboctahedra that share corners with four equivalent Na(3)O12 cuboctahedra, corners with four equivalent Na(4)O12 cuboctahedra, corners with four equivalent Ce(3)O12 cuboctahedra,  a faceface with one Na(3)O12 cuboctahedra,  a faceface with one Na(4)O12 cuboctahedra, faces with four equivalent Ce(3)O12 cuboctahedra, faces with four equivalent Ti(5)O6 octahedra, and faces with four equivalent Ti(7)O6 octahedra. All Ce(3)-O(12) bond lengths are 2.66 Å. All Ce(3)-O(13) bond lengths are 2.79 Å. All Ce(3)-O(3) bond lengths are 2.60 Å. There are eight inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(6), one O(7), and four equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Ti(4)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, faces with four equivalent Na(2)O12 cuboctahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-15°. The Ti(1)-O(6) bond length is 1.97 Å. The Ti(1)-O(7) bond length is 1.91 Å. All Ti(1)-O(2) bond lengths are 1.99 Å. In the second Ti site, Ti(2) is bonded to one O(5), one O(6), and four equivalent O(1) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with four equivalent Na(1)O12 cuboctahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-12°. The Ti(2)-O(5) bond length is 1.88 Å. The Ti(2)-O(6) bond length is 1.96 Å. All Ti(2)-O(1) bond lengths are 1.98 Å. In the third Ti site, Ti(3) is bonded to one O(10), one O(8), and four equivalent O(11) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(4)O6 octahedra,  a cornercorner with one Ti(5)O6 octahedra, corners with four equivalent Ti(3)O6 octahedra, faces with four equivalent Na(3)O12 cuboctahedra, and faces with four equivalent Ce(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-15°. The Ti(3)-O(10) bond length is 1.89 Å. The Ti(3)-O(8) bond length is 2.01 Å. All Ti(3)-O(11) bond lengths are 1.99 Å. In the fourth Ti site, Ti(4) is bonded to one O(7), one O(8), and four equivalent O(9) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Ti(3)O6 octahedra, corners with four equivalent Ti(4)O6 octahedra, faces with four equivalent Na(2)O12 cuboctahedra, and faces with four equivalent Ce(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-13°. The Ti(4)-O(7) bond length is 1.93 Å. The Ti(4)-O(8) bond length is 1.97 Å. All Ti(4)-O(9) bond lengths are 1.99 Å. In the fifth Ti site, Ti(5) is bonded to one O(10), one O(13), and four equivalent O(12) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Ti(7)O6 octahedra, corners with four equivalent Ti(5)O6 octahedra, faces with four equivalent Na(3)O12 cuboctahedra, and faces with four equivalent Ce(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-12°. The Ti(5)-O(10) bond length is 1.95 Å. The Ti(5)-O(13) bond length is 1.95 Å. All Ti(5)-O(12) bond lengths are 1.98 Å. In the sixth Ti site, Ti(6) is bonded to one O(14), one O(17), and four equivalent O(15) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(7)O6 octahedra,  a cornercorner with one Ti(8)O6 octahedra, corners with four equivalent Ti(6)O6 octahedra, faces with four equivalent Na(4)O12 cuboctahedra, and faces with four equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-9°. The Ti(6)-O(14) bond length is 1.96 Å. The Ti(6)-O(17) bond length is 1.99 Å. All Ti(6)-O(15) bond lengths are 1.98 Å. In the seventh Ti site, Ti(7) is bonded to one O(13), one O(14), and four equivalent O(3) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(5)O6 octahedra,  a cornercorner with one Ti(6)O6 octahedra, corners with four equivalent Ti(7)O6 octahedra, faces with four equivalent Na(4)O12 cuboctahedra, and faces with four equivalent Ce(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-17°. The Ti(7)-O(13) bond length is 2.03 Å. The Ti(7)-O(14) bond length is 1.86 Å. All Ti(7)-O(3) bond lengths are 1.99 Å. In the eighth Ti site, Ti(8) is bonded to one O(17), one O(19), and four equivalent O(16) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(6)O6 octahedra,  a cornercorner with one Nb(1)O6 octahedra, corners with four equivalent Ti(8)O6 octahedra, faces with four equivalent Ca(1)O12 cuboctahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-8°. The Ti(8)-O(17) bond length is 1.86 Å. The Ti(8)-O(19) bond length is 1.99 Å. All Ti(8)-O(16) bond lengths are 1.98 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(19), one O(20), and four equivalent O(18) atoms to form NbO6 octahedra that share  a cornercorner with one Ti(8)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, faces with four equivalent Na(5)O12 cuboctahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. The Nb(1)-O(19) bond length is 1.97 Å. The Nb(1)-O(20) bond length is 1.99 Å. All Nb(1)-O(18) bond lengths are 1.97 Å. In the second Nb site, Nb(2) is bonded to one O(20), one O(5), and four equivalent O(4) atoms to form NbO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra,  a cornercorner with one Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, faces with four equivalent Na(1)O12 cuboctahedra, and faces with four equivalent Na(5)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. The Nb(2)-O(20) bond length is 2.00 Å. The Nb(2)-O(5) bond length is 2.01 Å. All Nb(2)-O(4) bond lengths are 1.97 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1), two equivalent Ce(1), and two equivalent Ti(2) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Na(2), two equivalent Ce(1), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Na(4), two equivalent Ce(3), and two equivalent Ti(7) atoms. In the fourth O site, O(4) is bonded to two equivalent Na(1), two equivalent Na(5), and two equivalent Nb(2) atoms to form a mixture of distorted face, corner, and edge-sharing ONa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 1-58°. In the fifth O site, O(5) is bonded in a distorted linear geometry to four equivalent Na(1), one Ti(2), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a linear geometry to four equivalent Ce(1), one Ti(1), and one Ti(2) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to four equivalent Na(2), one Ti(1), and one Ti(4) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to four equivalent Ce(2), one Ti(3), and one Ti(4) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to two equivalent Na(2), two equivalent Ce(2), and two equivalent Ti(4) atoms. In the tenth O site, O(10) is bonded in a distorted linear geometry to four equivalent Na(3), one Ti(3), and one Ti(5) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to two equivalent Na(3), two equivalent Ce(2), and two equivalent Ti(3) atoms. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to two equivalent Na(3), two equivalent Ce(3), and two equivalent Ti(5) atoms. In the thirteenth O site, O(13) is bonded in a distorted linear geometry to four equivalent Ce(3), one Ti(5), and one Ti(7) atom. In the fourteenth O site, O(14) is bonded in a distorted linear geometry to four equivalent Na(4), one Ti(6), and one Ti(7) atom. In the fifteenth O site, O(15) is bonded to two equivalent Na(4), two equivalent Ca(1), and two equivalent Ti(6) atoms to form a mixture of distorted face, corner, and edge-sharing ONa2Ca2Ti2 octahedra. The corner-sharing octahedral tilt angles are 9°. In the sixteenth O site, O(16) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Ti(8) atoms. In the seventeenth O site, O(17) is bonded in a distorted linear geometry to four equivalent Ca(1), one Ti(6), and one Ti(8) atom. In the eighteenth O site, O(18) is bonded in a distorted linear geometry to two equivalent Na(5), two equivalent Ca(2), and two equivalent Nb(1) atoms. In the nineteenth O site, O(19) is bonded in a distorted linear geometry to four equivalent Ca(2), one Ti(8), and one Nb(1) atom. In the twentieth O site, O(20) is bonded to four equivalent Na(5), one Nb(1), and one Nb(2) atom to form a mixture of distorted face, corner, and edge-sharing ONa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 3-58°.