Th2Fe7 crystallizes in the trigonal R-3m space group. There are six inequivalent Th sites. In the first Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(4), and six equivalent Fe(5) atoms. In the second Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(4), and six equivalent Fe(5) atoms. In the third Th site, Th(2) is bonded in a 12-coordinate geometry to three equivalent Fe(1) and nine equivalent Fe(5) atoms. In the fourth Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2); three equivalent Fe(3); six Fe(4,4,4); and six equivalent Fe(5) atoms. In the fifth Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2); three equivalent Fe(3); six Fe(4,4,4); and six equivalent Fe(5) atoms. In the sixth Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(4), and six equivalent Fe(5) atoms. There are seven inequivalent Fe sites. In the first Fe site, Fe(4) is bonded to four Th(1,1); two equivalent Fe(2); two equivalent Fe(3); and four Fe(4,4) atoms to form FeTh4Fe8 cuboctahedra that share corners with four equivalent Fe(4)Th4Fe8 cuboctahedra; corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra; edges with two equivalent Fe(4)Th4Fe8 cuboctahedra; edges with eight equivalent Fe(5)Th5Fe7 cuboctahedra; faces with two equivalent Fe(5)Th5Fe7 cuboctahedra; and faces with eight Fe(4,4)Th4Fe8 cuboctahedra. In the second Fe site, Fe(1) is bonded to six equivalent Th(2) and six equivalent Fe(5) atoms to form FeTh6Fe6 cuboctahedra that share corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra, edges with six equivalent Fe(1)Th6Fe6 cuboctahedra, and faces with eighteen equivalent Fe(5)Th5Fe7 cuboctahedra. In the third Fe site, Fe(2) is bonded in a 9-coordinate geometry to three equivalent Th(1), three equivalent Fe(4), and three equivalent Fe(5) atoms. In the fourth Fe site, Fe(3) is bonded in a 9-coordinate geometry to three equivalent Th(1), three equivalent Fe(4), and three equivalent Fe(5) atoms. In the fifth Fe site, Fe(4) is bonded to four equivalent Th(1), two equivalent Fe(2), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeTh4Fe8 cuboctahedra that share corners with four equivalent Fe(4)Th4Fe8 cuboctahedra, corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra, edges with two equivalent Fe(4)Th4Fe8 cuboctahedra, edges with eight equivalent Fe(5)Th5Fe7 cuboctahedra, faces with two equivalent Fe(5)Th5Fe7 cuboctahedra, and faces with eight equivalent Fe(4)Th4Fe8 cuboctahedra. In the sixth Fe site, Fe(5) is bonded to two equivalent Th(1), three equivalent Th(2), one Fe(1), one Fe(2), one Fe(3), and four equivalent Fe(5) atoms to form distorted FeTh5Fe7 cuboctahedra that share corners with two equivalent Fe(1)Th6Fe6 cuboctahedra, corners with six equivalent Fe(4)Th4Fe8 cuboctahedra, corners with nine equivalent Fe(5)Th5Fe7 cuboctahedra, edges with four equivalent Fe(4)Th4Fe8 cuboctahedra, edges with four equivalent Fe(5)Th5Fe7 cuboctahedra,  a faceface with one Fe(4)Th4Fe8 cuboctahedra, faces with three equivalent Fe(1)Th6Fe6 cuboctahedra, and faces with ten equivalent Fe(5)Th5Fe7 cuboctahedra. In the seventh Fe site, Fe(4) is bonded to four Th(1,1); two equivalent Fe(2); two equivalent Fe(3); and four Fe(4,4) atoms to form FeTh4Fe8 cuboctahedra that share corners with four equivalent Fe(4)Th4Fe8 cuboctahedra; corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra; edges with two equivalent Fe(4)Th4Fe8 cuboctahedra; edges with eight equivalent Fe(5)Th5Fe7 cuboctahedra; faces with two equivalent Fe(5)Th5Fe7 cuboctahedra; and faces with eight Fe(4,4)Th4Fe8 cuboctahedra.
Th2Fe7 crystallizes in the trigonal R-3m space group. There are six inequivalent Th sites. In the first Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(4), and six equivalent Fe(5) atoms. All Th(1)-Fe(2) bond lengths are 2.96 Å. All Th(1)-Fe(3) bond lengths are 2.96 Å. All Th(1)-Fe(4) bond lengths are 3.18 Å. All Th(1)-Fe(5) bond lengths are 3.36 Å. In the second Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(4), and six equivalent Fe(5) atoms. All Th(1)-Fe(2) bond lengths are 2.96 Å. All Th(1)-Fe(3) bond lengths are 2.96 Å. All Th(1)-Fe(4) bond lengths are 3.18 Å. All Th(1)-Fe(5) bond lengths are 3.36 Å. In the third Th site, Th(2) is bonded in a 12-coordinate geometry to three equivalent Fe(1) and nine equivalent Fe(5) atoms. All Th(2)-Fe(1) bond lengths are 3.03 Å. There are six shorter (2.93 Å) and three longer (3.15 Å) Th(2)-Fe(5) bond lengths. In the fourth Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2); three equivalent Fe(3); six Fe(4,4,4); and six equivalent Fe(5) atoms. All Th(1)-Fe(2) bond lengths are 2.96 Å. All Th(1)-Fe(3) bond lengths are 2.96 Å. All Th(1)-Fe(4,4,4) bond lengths are 3.18 Å. All Th(1)-Fe(5) bond lengths are 3.36 Å. In the fifth Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2); three equivalent Fe(3); six Fe(4,4,4); and six equivalent Fe(5) atoms. All Th(1)-Fe(2) bond lengths are 2.96 Å. All Th(1)-Fe(3) bond lengths are 2.96 Å. All Th(1)-Fe(4,4,4) bond lengths are 3.18 Å. All Th(1)-Fe(5) bond lengths are 3.36 Å. In the sixth Th site, Th(1) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(4), and six equivalent Fe(5) atoms. All Th(1)-Fe(2) bond lengths are 2.96 Å. All Th(1)-Fe(3) bond lengths are 2.96 Å. All Th(1)-Fe(4) bond lengths are 3.18 Å. All Th(1)-Fe(5) bond lengths are 3.36 Å. There are seven inequivalent Fe sites. In the first Fe site, Fe(4) is bonded to four Th(1,1); two equivalent Fe(2); two equivalent Fe(3); and four Fe(4,4) atoms to form FeTh4Fe8 cuboctahedra that share corners with four equivalent Fe(4)Th4Fe8 cuboctahedra; corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra; edges with two equivalent Fe(4)Th4Fe8 cuboctahedra; edges with eight equivalent Fe(5)Th5Fe7 cuboctahedra; faces with two equivalent Fe(5)Th5Fe7 cuboctahedra; and faces with eight Fe(4,4)Th4Fe8 cuboctahedra. Both Fe(4)-Fe(2) bond lengths are 2.54 Å. Both Fe(4)-Fe(3) bond lengths are 2.53 Å. All Fe(4)-Fe(4,4) bond lengths are 2.56 Å. In the second Fe site, Fe(1) is bonded to six equivalent Th(2) and six equivalent Fe(5) atoms to form FeTh6Fe6 cuboctahedra that share corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra, edges with six equivalent Fe(1)Th6Fe6 cuboctahedra, and faces with eighteen equivalent Fe(5)Th5Fe7 cuboctahedra. All Fe(1)-Fe(5) bond lengths are 2.58 Å. In the third Fe site, Fe(2) is bonded in a 9-coordinate geometry to three equivalent Th(1), three equivalent Fe(4), and three equivalent Fe(5) atoms. All Fe(2)-Fe(4) bond lengths are 2.54 Å. All Fe(2)-Fe(5) bond lengths are 2.48 Å. In the fourth Fe site, Fe(3) is bonded in a 9-coordinate geometry to three equivalent Th(1), three equivalent Fe(4), and three equivalent Fe(5) atoms. All Fe(3)-Fe(4) bond lengths are 2.53 Å. All Fe(3)-Fe(5) bond lengths are 2.50 Å. In the fifth Fe site, Fe(4) is bonded to four equivalent Th(1), two equivalent Fe(2), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeTh4Fe8 cuboctahedra that share corners with four equivalent Fe(4)Th4Fe8 cuboctahedra, corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra, edges with two equivalent Fe(4)Th4Fe8 cuboctahedra, edges with eight equivalent Fe(5)Th5Fe7 cuboctahedra, faces with two equivalent Fe(5)Th5Fe7 cuboctahedra, and faces with eight equivalent Fe(4)Th4Fe8 cuboctahedra. All Fe(4)-Fe(4) bond lengths are 2.56 Å. In the sixth Fe site, Fe(5) is bonded to two equivalent Th(1), three equivalent Th(2), one Fe(1), one Fe(2), one Fe(3), and four equivalent Fe(5) atoms to form distorted FeTh5Fe7 cuboctahedra that share corners with two equivalent Fe(1)Th6Fe6 cuboctahedra, corners with six equivalent Fe(4)Th4Fe8 cuboctahedra, corners with nine equivalent Fe(5)Th5Fe7 cuboctahedra, edges with four equivalent Fe(4)Th4Fe8 cuboctahedra, edges with four equivalent Fe(5)Th5Fe7 cuboctahedra,  a faceface with one Fe(4)Th4Fe8 cuboctahedra, faces with three equivalent Fe(1)Th6Fe6 cuboctahedra, and faces with ten equivalent Fe(5)Th5Fe7 cuboctahedra. There are two shorter (2.55 Å) and two longer (2.57 Å) Fe(5)-Fe(5) bond lengths. In the seventh Fe site, Fe(4) is bonded to four Th(1,1); two equivalent Fe(2); two equivalent Fe(3); and four Fe(4,4) atoms to form FeTh4Fe8 cuboctahedra that share corners with four equivalent Fe(4)Th4Fe8 cuboctahedra; corners with twelve equivalent Fe(5)Th5Fe7 cuboctahedra; edges with two equivalent Fe(4)Th4Fe8 cuboctahedra; edges with eight equivalent Fe(5)Th5Fe7 cuboctahedra; faces with two equivalent Fe(5)Th5Fe7 cuboctahedra; and faces with eight Fe(4,4)Th4Fe8 cuboctahedra. Both Fe(4)-Fe(2) bond lengths are 2.54 Å. Both Fe(4)-Fe(3) bond lengths are 2.53 Å. Both Fe(4)-Fe(4) bond lengths are 2.56 Å.