Ce2Ir7 crystallizes in the trigonal R-3m space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 18-coordinate geometry to three equivalent Ir(2); three equivalent Ir(3); six Ir(4,4); and six equivalent Ir(5) atoms. In the second Ce site, Ce(2) is bonded in a 12-coordinate geometry to three equivalent Ir(1) and nine equivalent Ir(5) atoms. In the third Ce site, Ce(1) is bonded in a 18-coordinate geometry to three equivalent Ir(2); three equivalent Ir(3); six Ir(4,4); and six equivalent Ir(5) atoms. In the fourth Ce site, Ce(1) is bonded in a 18-coordinate geometry to three equivalent Ir(2); three equivalent Ir(3); six Ir(4,4); and six equivalent Ir(5) atoms. There are eight inequivalent Ir sites. In the first Ir site, Ir(4) is bonded to four Ce(1,1); two equivalent Ir(2); two equivalent Ir(3); and four equivalent Ir(4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra, corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra, edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra, edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra, faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra, and faces with eight equivalent Ir(4)Ce4Ir8 cuboctahedra. In the second Ir site, Ir(1) is bonded to six equivalent Ce(2) and six equivalent Ir(5) atoms to form IrCe6Ir6 cuboctahedra that share corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra, edges with six equivalent Ir(1)Ce6Ir6 cuboctahedra, and faces with eighteen equivalent Ir(5)Ce5Ir7 cuboctahedra. In the third Ir site, Ir(2) is bonded in a 12-coordinate geometry to three equivalent Ce(1), three equivalent Ir(3), three equivalent Ir(4), and three equivalent Ir(5) atoms. In the fourth Ir site, Ir(4) is bonded to four Ce(1,1); two equivalent Ir(2); two equivalent Ir(3); and four Ir(4,4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra; corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra; edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra; edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra; faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra; and faces with eight Ir(4,4)Ce4Ir8 cuboctahedra. In the fifth Ir site, Ir(3) is bonded in a 12-coordinate geometry to three equivalent Ce(1); three equivalent Ir(2); three Ir(4,4); and three equivalent Ir(5) atoms. In the sixth Ir site, Ir(4) is bonded to four equivalent Ce(1), two equivalent Ir(2), two equivalent Ir(3), and four equivalent Ir(4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra, corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra, edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra, edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra, faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra, and faces with eight equivalent Ir(4)Ce4Ir8 cuboctahedra. In the seventh Ir site, Ir(5) is bonded to two equivalent Ce(1), three equivalent Ce(2), one Ir(1), one Ir(2), one Ir(3), and four equivalent Ir(5) atoms to form distorted IrCe5Ir7 cuboctahedra that share corners with two equivalent Ir(1)Ce6Ir6 cuboctahedra; corners with six Ir(4,4)Ce4Ir8 cuboctahedra; corners with nine equivalent Ir(5)Ce5Ir7 cuboctahedra; edges with four Ir(4,4)Ce4Ir8 cuboctahedra; edges with four equivalent Ir(5)Ce5Ir7 cuboctahedra;  a faceface with one Ir(4)Ce4Ir8 cuboctahedra; faces with three equivalent Ir(1)Ce6Ir6 cuboctahedra; and faces with ten equivalent Ir(5)Ce5Ir7 cuboctahedra. In the eighth Ir site, Ir(4) is bonded to four Ce(1,1); two equivalent Ir(2); two equivalent Ir(3); and four Ir(4,4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra; corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra; edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra; edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra; faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra; and faces with eight Ir(4,4)Ce4Ir8 cuboctahedra.
Ce2Ir7 crystallizes in the trigonal R-3m space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 18-coordinate geometry to three equivalent Ir(2); three equivalent Ir(3); six Ir(4,4); and six equivalent Ir(5) atoms. All Ce(1)-Ir(2) bond lengths are 3.08 Å. All Ce(1)-Ir(3) bond lengths are 3.08 Å. All Ce(1)-Ir(4,4) bond lengths are 3.33 Å. All Ce(1)-Ir(5) bond lengths are 3.57 Å. In the second Ce site, Ce(2) is bonded in a 12-coordinate geometry to three equivalent Ir(1) and nine equivalent Ir(5) atoms. All Ce(2)-Ir(1) bond lengths are 3.17 Å. There are six shorter (3.03 Å) and three longer (3.37 Å) Ce(2)-Ir(5) bond lengths. In the third Ce site, Ce(1) is bonded in a 18-coordinate geometry to three equivalent Ir(2); three equivalent Ir(3); six Ir(4,4); and six equivalent Ir(5) atoms. All Ce(1)-Ir(2) bond lengths are 3.08 Å. All Ce(1)-Ir(3) bond lengths are 3.08 Å. All Ce(1)-Ir(4,4) bond lengths are 3.33 Å. All Ce(1)-Ir(5) bond lengths are 3.57 Å. In the fourth Ce site, Ce(1) is bonded in a 18-coordinate geometry to three equivalent Ir(2); three equivalent Ir(3); six Ir(4,4); and six equivalent Ir(5) atoms. All Ce(1)-Ir(2) bond lengths are 3.08 Å. All Ce(1)-Ir(3) bond lengths are 3.08 Å. All Ce(1)-Ir(4,4) bond lengths are 3.33 Å. All Ce(1)-Ir(5) bond lengths are 3.57 Å. There are eight inequivalent Ir sites. In the first Ir site, Ir(4) is bonded to four Ce(1,1); two equivalent Ir(2); two equivalent Ir(3); and four equivalent Ir(4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra, corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra, edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra, edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra, faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra, and faces with eight equivalent Ir(4)Ce4Ir8 cuboctahedra. Both Ir(4)-Ir(2) bond lengths are 2.68 Å. Both Ir(4)-Ir(3) bond lengths are 2.69 Å. All Ir(4)-Ir(4) bond lengths are 2.66 Å. In the second Ir site, Ir(1) is bonded to six equivalent Ce(2) and six equivalent Ir(5) atoms to form IrCe6Ir6 cuboctahedra that share corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra, edges with six equivalent Ir(1)Ce6Ir6 cuboctahedra, and faces with eighteen equivalent Ir(5)Ce5Ir7 cuboctahedra. All Ir(1)-Ir(5) bond lengths are 2.71 Å. In the third Ir site, Ir(2) is bonded in a 12-coordinate geometry to three equivalent Ce(1), three equivalent Ir(3), three equivalent Ir(4), and three equivalent Ir(5) atoms. All Ir(2)-Ir(3) bond lengths are 3.08 Å. All Ir(2)-Ir(4) bond lengths are 2.68 Å. All Ir(2)-Ir(5) bond lengths are 2.66 Å. In the fourth Ir site, Ir(4) is bonded to four Ce(1,1); two equivalent Ir(2); two equivalent Ir(3); and four Ir(4,4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra; corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra; edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra; edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra; faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra; and faces with eight Ir(4,4)Ce4Ir8 cuboctahedra. Both Ir(4)-Ce(1) bond lengths are 3.33 Å. Both Ir(4)-Ir(2) bond lengths are 2.68 Å. Both Ir(4)-Ir(3) bond lengths are 2.69 Å. All Ir(4)-Ir(4,4) bond lengths are 2.66 Å. In the fifth Ir site, Ir(3) is bonded in a 12-coordinate geometry to three equivalent Ce(1); three equivalent Ir(2); three Ir(4,4); and three equivalent Ir(5) atoms. Both Ir(3)-Ir(4) bond lengths are 2.69 Å. All Ir(3)-Ir(5) bond lengths are 2.66 Å. In the sixth Ir site, Ir(4) is bonded to four equivalent Ce(1), two equivalent Ir(2), two equivalent Ir(3), and four equivalent Ir(4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra, corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra, edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra, edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra, faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra, and faces with eight equivalent Ir(4)Ce4Ir8 cuboctahedra. All Ir(4)-Ce(1) bond lengths are 3.33 Å. Both Ir(4)-Ir(3) bond lengths are 2.69 Å. All Ir(4)-Ir(4) bond lengths are 2.66 Å. In the seventh Ir site, Ir(5) is bonded to two equivalent Ce(1), three equivalent Ce(2), one Ir(1), one Ir(2), one Ir(3), and four equivalent Ir(5) atoms to form distorted IrCe5Ir7 cuboctahedra that share corners with two equivalent Ir(1)Ce6Ir6 cuboctahedra; corners with six Ir(4,4)Ce4Ir8 cuboctahedra; corners with nine equivalent Ir(5)Ce5Ir7 cuboctahedra; edges with four Ir(4,4)Ce4Ir8 cuboctahedra; edges with four equivalent Ir(5)Ce5Ir7 cuboctahedra;  a faceface with one Ir(4)Ce4Ir8 cuboctahedra; faces with three equivalent Ir(1)Ce6Ir6 cuboctahedra; and faces with ten equivalent Ir(5)Ce5Ir7 cuboctahedra. There are two shorter (2.65 Å) and two longer (2.68 Å) Ir(5)-Ir(5) bond lengths. In the eighth Ir site, Ir(4) is bonded to four Ce(1,1); two equivalent Ir(2); two equivalent Ir(3); and four Ir(4,4) atoms to form IrCe4Ir8 cuboctahedra that share corners with four equivalent Ir(4)Ce4Ir8 cuboctahedra; corners with twelve equivalent Ir(5)Ce5Ir7 cuboctahedra; edges with two equivalent Ir(4)Ce4Ir8 cuboctahedra; edges with eight equivalent Ir(5)Ce5Ir7 cuboctahedra; faces with two equivalent Ir(5)Ce5Ir7 cuboctahedra; and faces with eight Ir(4,4)Ce4Ir8 cuboctahedra. Both Ir(4)-Ir(2) bond lengths are 2.68 Å. Both Ir(4)-Ir(4) bond lengths are 2.66 Å.