Ce3Ti6Fe23 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 14-coordinate geometry to one Ti(3), one Fe(1), two equivalent Fe(2), two equivalent Fe(4), two equivalent Fe(7), four equivalent Fe(6), and six equivalent Fe(3) atoms. In the second Ce site, Ce(2) is bonded in a 20-coordinate geometry to two equivalent Ti(1), two equivalent Ti(2), two equivalent Fe(1), two equivalent Fe(4), four equivalent Fe(2), four equivalent Fe(5), and four equivalent Fe(7) atoms. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 12-coordinate geometry to one Ce(2), one Ti(3), one Fe(1), one Fe(4), two equivalent Fe(2), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Fe(7) atoms. In the second Ti site, Ti(2) is bonded in a 10-coordinate geometry to one Ce(2), one Ti(2), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(5), and two equivalent Fe(7) atoms. In the third Ti site, Ti(3) is bonded in a 12-coordinate geometry to one Ce(1), one Ti(1), one Fe(1), one Fe(8), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(6), and two equivalent Fe(7) atoms. There are eight inequivalent Fe sites. In the first Fe site, Fe(6) is bonded to two equivalent Ce(1), one Ti(1), one Ti(3), one Fe(2), one Fe(4), one Fe(6), one Fe(7), one Fe(8), and three equivalent Fe(3) atoms to form distorted FeCe2Ti2Fe8 cuboctahedra that share  a cornercorner with one Fe(5)Ce2Ti4Fe6 cuboctahedra,  a cornercorner with one Fe(4)Ce3TiFe8 cuboctahedra, corners with three equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(3)Ce3TiFe8 cuboctahedra, corners with six equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra,  an edgeedge with one Fe(3)Ce3TiFe8 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  a faceface with one Fe(5)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, faces with three equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, and faces with six equivalent Fe(3)Ce3TiFe8 cuboctahedra. In the second Fe site, Fe(7) is bonded in a 12-coordinate geometry to one Ce(1), one Ce(2), one Ti(1), one Ti(2), one Ti(3), one Fe(1), one Fe(3), one Fe(4), one Fe(5), one Fe(6), and two equivalent Fe(2) atoms. In the third Fe site, Fe(8) is bonded in a 10-coordinate geometry to two equivalent Ti(3), four equivalent Fe(3), and four equivalent Fe(6) atoms. In the fourth Fe site, Fe(1) is bonded to one Ce(1), one Ce(2), one Ti(1), one Ti(3), two equivalent Ti(2), two equivalent Fe(2), two equivalent Fe(5), and two equivalent Fe(7) atoms to form distorted FeCe2Ti4Fe6 cuboctahedra that share corners with two equivalent Fe(3)Ce3TiFe8 cuboctahedra, corners with three equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with three equivalent Fe(4)Ce3TiFe8 cuboctahedra, corners with four equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, corners with six equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra,  an edgeedge with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra, edges with two equivalent Fe(3)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(4)Ce3TiFe8 cuboctahedra, faces with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, faces with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, and faces with two equivalent Fe(3)Ce3TiFe8 cuboctahedra. In the fifth Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Ce(1), one Ce(2), one Ti(1), one Ti(2), one Ti(3), one Fe(1), one Fe(3), one Fe(4), one Fe(5), one Fe(6), and two equivalent Fe(7) atoms. In the sixth Fe site, Fe(3) is bonded to three equivalent Ce(1), one Ti(3), one Fe(2), one Fe(3), one Fe(4), one Fe(7), one Fe(8), and three equivalent Fe(6) atoms to form distorted FeCe3TiFe8 cuboctahedra that share  a cornercorner with one Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, corners with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, corners with four equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, corners with five equivalent Fe(3)Ce3TiFe8 cuboctahedra,  an edgeedge with one Fe(6)Ce2Ti2Fe8 cuboctahedra,  an edgeedge with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra, edges with three equivalent Fe(3)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(1)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, faces with four equivalent Fe(3)Ce3TiFe8 cuboctahedra, and faces with six equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra. In the seventh Fe site, Fe(4) is bonded to one Ce(2), two equivalent Ce(1), one Ti(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(6), and two equivalent Fe(7) atoms to form distorted FeCe3TiFe8 cuboctahedra that share  a cornercorner with one Fe(4)Ce3TiFe8 cuboctahedra, corners with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, corners with three equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(3)Ce3TiFe8 cuboctahedra,  an edgeedge with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra, edges with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, edges with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, edges with two equivalent Fe(3)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(1)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, faces with four equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, and faces with four equivalent Fe(3)Ce3TiFe8 cuboctahedra. In the eighth Fe site, Fe(5) is bonded to two equivalent Ce(2), two equivalent Ti(1), two equivalent Ti(2), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(7) atoms to form distorted FeCe2Ti4Fe6 cuboctahedra that share corners with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, corners with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(3)Ce3TiFe8 cuboctahedra, edges with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, edges with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, faces with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, faces with two equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, and faces with two equivalent Fe(4)Ce3TiFe8 cuboctahedra.
Ce3Ti6Fe23 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 14-coordinate geometry to one Ti(3), one Fe(1), two equivalent Fe(2), two equivalent Fe(4), two equivalent Fe(7), four equivalent Fe(6), and six equivalent Fe(3) atoms. The Ce(1)-Ti(3) bond length is 3.16 Å. The Ce(1)-Fe(1) bond length is 3.16 Å. Both Ce(1)-Fe(2) bond lengths are 3.04 Å. There is one shorter (2.96 Å) and one longer (3.16 Å) Ce(1)-Fe(4) bond length. Both Ce(1)-Fe(7) bond lengths are 3.36 Å. There are two shorter (3.04 Å) and two longer (3.08 Å) Ce(1)-Fe(6) bond lengths. There are a spread of Ce(1)-Fe(3) bond distances ranging from 3.04-3.38 Å. In the second Ce site, Ce(2) is bonded in a 20-coordinate geometry to two equivalent Ti(1), two equivalent Ti(2), two equivalent Fe(1), two equivalent Fe(4), four equivalent Fe(2), four equivalent Fe(5), and four equivalent Fe(7) atoms. Both Ce(2)-Ti(1) bond lengths are 3.01 Å. Both Ce(2)-Ti(2) bond lengths are 2.99 Å. Both Ce(2)-Fe(1) bond lengths are 3.03 Å. Both Ce(2)-Fe(4) bond lengths are 3.17 Å. All Ce(2)-Fe(2) bond lengths are 3.04 Å. All Ce(2)-Fe(5) bond lengths are 3.27 Å. All Ce(2)-Fe(7) bond lengths are 3.33 Å. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 12-coordinate geometry to one Ce(2), one Ti(3), one Fe(1), one Fe(4), two equivalent Fe(2), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Fe(7) atoms. The Ti(1)-Ti(3) bond length is 2.66 Å. The Ti(1)-Fe(1) bond length is 2.65 Å. The Ti(1)-Fe(4) bond length is 2.61 Å. Both Ti(1)-Fe(2) bond lengths are 2.80 Å. Both Ti(1)-Fe(5) bond lengths are 2.61 Å. Both Ti(1)-Fe(6) bond lengths are 2.84 Å. Both Ti(1)-Fe(7) bond lengths are 2.61 Å. In the second Ti site, Ti(2) is bonded in a 10-coordinate geometry to one Ce(2), one Ti(2), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(5), and two equivalent Fe(7) atoms. The Ti(2)-Ti(2) bond length is 2.67 Å. Both Ti(2)-Fe(1) bond lengths are 2.78 Å. Both Ti(2)-Fe(2) bond lengths are 2.63 Å. Both Ti(2)-Fe(5) bond lengths are 2.60 Å. Both Ti(2)-Fe(7) bond lengths are 2.66 Å. In the third Ti site, Ti(3) is bonded in a 12-coordinate geometry to one Ce(1), one Ti(1), one Fe(1), one Fe(8), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(6), and two equivalent Fe(7) atoms. The Ti(3)-Fe(1) bond length is 2.63 Å. The Ti(3)-Fe(8) bond length is 2.56 Å. Both Ti(3)-Fe(2) bond lengths are 2.77 Å. Both Ti(3)-Fe(3) bond lengths are 2.65 Å. Both Ti(3)-Fe(6) bond lengths are 2.86 Å. Both Ti(3)-Fe(7) bond lengths are 2.59 Å. There are eight inequivalent Fe sites. In the first Fe site, Fe(6) is bonded to two equivalent Ce(1), one Ti(1), one Ti(3), one Fe(2), one Fe(4), one Fe(6), one Fe(7), one Fe(8), and three equivalent Fe(3) atoms to form distorted FeCe2Ti2Fe8 cuboctahedra that share  a cornercorner with one Fe(5)Ce2Ti4Fe6 cuboctahedra,  a cornercorner with one Fe(4)Ce3TiFe8 cuboctahedra, corners with three equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(3)Ce3TiFe8 cuboctahedra, corners with six equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra,  an edgeedge with one Fe(3)Ce3TiFe8 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  a faceface with one Fe(5)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, faces with three equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, and faces with six equivalent Fe(3)Ce3TiFe8 cuboctahedra. The Fe(6)-Fe(2) bond length is 2.50 Å. The Fe(6)-Fe(4) bond length is 2.60 Å. The Fe(6)-Fe(6) bond length is 2.51 Å. The Fe(6)-Fe(7) bond length is 2.48 Å. The Fe(6)-Fe(8) bond length is 2.46 Å. There are a spread of Fe(6)-Fe(3) bond distances ranging from 2.60-2.67 Å. In the second Fe site, Fe(7) is bonded in a 12-coordinate geometry to one Ce(1), one Ce(2), one Ti(1), one Ti(2), one Ti(3), one Fe(1), one Fe(3), one Fe(4), one Fe(5), one Fe(6), and two equivalent Fe(2) atoms. The Fe(7)-Fe(1) bond length is 2.48 Å. The Fe(7)-Fe(3) bond length is 2.43 Å. The Fe(7)-Fe(4) bond length is 2.49 Å. The Fe(7)-Fe(5) bond length is 2.42 Å. There is one shorter (2.46 Å) and one longer (2.49 Å) Fe(7)-Fe(2) bond length. In the third Fe site, Fe(8) is bonded in a 10-coordinate geometry to two equivalent Ti(3), four equivalent Fe(3), and four equivalent Fe(6) atoms. All Fe(8)-Fe(3) bond lengths are 2.49 Å. In the fourth Fe site, Fe(1) is bonded to one Ce(1), one Ce(2), one Ti(1), one Ti(3), two equivalent Ti(2), two equivalent Fe(2), two equivalent Fe(5), and two equivalent Fe(7) atoms to form distorted FeCe2Ti4Fe6 cuboctahedra that share corners with two equivalent Fe(3)Ce3TiFe8 cuboctahedra, corners with three equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with three equivalent Fe(4)Ce3TiFe8 cuboctahedra, corners with four equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, corners with six equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra,  an edgeedge with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra, edges with two equivalent Fe(3)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(4)Ce3TiFe8 cuboctahedra, faces with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, faces with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, and faces with two equivalent Fe(3)Ce3TiFe8 cuboctahedra. Both Fe(1)-Fe(2) bond lengths are 2.69 Å. Both Fe(1)-Fe(5) bond lengths are 2.49 Å. In the fifth Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Ce(1), one Ce(2), one Ti(1), one Ti(2), one Ti(3), one Fe(1), one Fe(3), one Fe(4), one Fe(5), one Fe(6), and two equivalent Fe(7) atoms. The Fe(2)-Fe(3) bond length is 2.55 Å. The Fe(2)-Fe(4) bond length is 2.73 Å. The Fe(2)-Fe(5) bond length is 2.53 Å. In the sixth Fe site, Fe(3) is bonded to three equivalent Ce(1), one Ti(3), one Fe(2), one Fe(3), one Fe(4), one Fe(7), one Fe(8), and three equivalent Fe(6) atoms to form distorted FeCe3TiFe8 cuboctahedra that share  a cornercorner with one Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, corners with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, corners with four equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, corners with five equivalent Fe(3)Ce3TiFe8 cuboctahedra,  an edgeedge with one Fe(6)Ce2Ti2Fe8 cuboctahedra,  an edgeedge with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra, edges with three equivalent Fe(3)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(1)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, faces with four equivalent Fe(3)Ce3TiFe8 cuboctahedra, and faces with six equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra. The Fe(3)-Fe(3) bond length is 2.43 Å. The Fe(3)-Fe(4) bond length is 2.48 Å. In the seventh Fe site, Fe(4) is bonded to one Ce(2), two equivalent Ce(1), one Ti(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(6), and two equivalent Fe(7) atoms to form distorted FeCe3TiFe8 cuboctahedra that share  a cornercorner with one Fe(4)Ce3TiFe8 cuboctahedra, corners with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, corners with three equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(3)Ce3TiFe8 cuboctahedra,  an edgeedge with one Fe(1)Ce2Ti4Fe6 cuboctahedra,  an edgeedge with one Fe(4)Ce3TiFe8 cuboctahedra, edges with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, edges with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, edges with two equivalent Fe(3)Ce3TiFe8 cuboctahedra,  a faceface with one Fe(1)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, faces with four equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, and faces with four equivalent Fe(3)Ce3TiFe8 cuboctahedra. In the eighth Fe site, Fe(5) is bonded to two equivalent Ce(2), two equivalent Ti(1), two equivalent Ti(2), two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(7) atoms to form distorted FeCe2Ti4Fe6 cuboctahedra that share corners with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, corners with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, corners with four equivalent Fe(3)Ce3TiFe8 cuboctahedra, edges with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, edges with two equivalent Fe(4)Ce3TiFe8 cuboctahedra, faces with two equivalent Fe(6)Ce2Ti2Fe8 cuboctahedra, faces with two equivalent Fe(1)Ce2Ti4Fe6 cuboctahedra, faces with two equivalent Fe(5)Ce2Ti4Fe6 cuboctahedra, and faces with two equivalent Fe(4)Ce3TiFe8 cuboctahedra.