Ca4Ir8As7 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 1-coordinate geometry to one Ir(1), one Ir(8), two equivalent Ir(4), one As(2), two equivalent As(1), two equivalent As(5), and two equivalent As(6) atoms. In the second Ca site, Ca(2) is bonded in a 1-coordinate geometry to one Ir(8), two equivalent Ir(2), three equivalent Ir(3), one As(1), two equivalent As(4), two equivalent As(5), and two equivalent As(7) atoms. In the third Ca site, Ca(3) is bonded in a 15-coordinate geometry to one Ir(3), one Ir(7), two equivalent Ir(2), two equivalent Ir(8), three equivalent Ir(5), two equivalent As(2), two equivalent As(3), and two equivalent As(7) atoms. In the fourth Ca site, Ca(4) is bonded in a 15-coordinate geometry to one Ir(4), one Ir(5), two equivalent Ir(2), two equivalent Ir(7), three equivalent Ir(1), two equivalent As(3), two equivalent As(4), and two equivalent As(6) atoms. There are eight inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to one Ca(1), three equivalent Ca(4), two equivalent Ir(1), two equivalent Ir(4), one As(4), and three equivalent As(6) atoms to form distorted face-sharing IrCa4As4Ir4 cuboctahedra. In the second Ir site, Ir(2) is bonded in a 9-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), two equivalent Ca(4), one As(3), one As(4), and one As(7) atom. In the third Ir site, Ir(3) is bonded to one Ca(3), three equivalent Ca(2), two equivalent Ir(3), two equivalent Ir(8), one As(5), and three equivalent As(7) atoms to form distorted face-sharing IrCa4As4Ir4 cuboctahedra. In the fourth Ir site, Ir(4) is bonded in a 7-coordinate geometry to one Ca(4), two equivalent Ca(1), two equivalent Ir(1), one As(1), one As(6), and two equivalent As(4) atoms. In the fifth Ir site, Ir(5) is bonded in a 12-coordinate geometry to one Ca(4), three equivalent Ca(3), two equivalent Ir(5), two equivalent Ir(7), one As(2), and three equivalent As(3) atoms. In the sixth Ir site, Ir(6) is bonded in a 4-coordinate geometry to one As(5) and three equivalent As(1) atoms. In the seventh Ir site, Ir(7) is bonded in a 7-coordinate geometry to one Ca(3), two equivalent Ca(4), two equivalent Ir(5), one As(3), one As(6), and two equivalent As(2) atoms. In the eighth Ir site, Ir(8) is bonded in a 10-coordinate geometry to one Ca(1), one Ca(2), two equivalent Ca(3), two equivalent Ir(3), one As(2), one As(7), and two equivalent As(5) atoms. There are seven inequivalent As sites. In the first As site, As(1) is bonded in a 7-coordinate geometry to one Ca(2), two equivalent Ca(1), one Ir(4), and three equivalent Ir(6) atoms. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Ca(1), two equivalent Ca(3), one Ir(5), one Ir(8), and two equivalent Ir(7) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Ca(3), two equivalent Ca(4), one Ir(2), one Ir(7), and three equivalent Ir(5) atoms. In the fourth As site, As(4) is bonded in a 8-coordinate geometry to two equivalent Ca(2), two equivalent Ca(4), one Ir(1), one Ir(2), and two equivalent Ir(4) atoms. In the fifth As site, As(5) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ir(3), one Ir(6), and two equivalent Ir(8) atoms. In the sixth As site, As(6) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(4), one Ir(4), one Ir(7), and three equivalent Ir(1) atoms. In the seventh As site, As(7) is bonded in a 9-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), one Ir(2), one Ir(8), and three equivalent Ir(3) atoms.
Ca4Ir8As7 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 1-coordinate geometry to one Ir(1), one Ir(8), two equivalent Ir(4), one As(2), two equivalent As(1), two equivalent As(5), and two equivalent As(6) atoms. The Ca(1)-Ir(1) bond length is 3.58 Å. The Ca(1)-Ir(8) bond length is 3.35 Å. Both Ca(1)-Ir(4) bond lengths are 3.15 Å. The Ca(1)-As(2) bond length is 2.88 Å. Both Ca(1)-As(1) bond lengths are 3.10 Å. Both Ca(1)-As(5) bond lengths are 3.45 Å. Both Ca(1)-As(6) bond lengths are 3.54 Å. In the second Ca site, Ca(2) is bonded in a 1-coordinate geometry to one Ir(8), two equivalent Ir(2), three equivalent Ir(3), one As(1), two equivalent As(4), two equivalent As(5), and two equivalent As(7) atoms. The Ca(2)-Ir(8) bond length is 3.29 Å. Both Ca(2)-Ir(2) bond lengths are 3.15 Å. There are two shorter (3.38 Å) and one longer (3.43 Å) Ca(2)-Ir(3) bond length. The Ca(2)-As(1) bond length is 2.98 Å. Both Ca(2)-As(4) bond lengths are 3.42 Å. Both Ca(2)-As(5) bond lengths are 3.31 Å. Both Ca(2)-As(7) bond lengths are 3.16 Å. In the third Ca site, Ca(3) is bonded in a 15-coordinate geometry to one Ir(3), one Ir(7), two equivalent Ir(2), two equivalent Ir(8), three equivalent Ir(5), two equivalent As(2), two equivalent As(3), and two equivalent As(7) atoms. The Ca(3)-Ir(3) bond length is 3.25 Å. The Ca(3)-Ir(7) bond length is 3.25 Å. Both Ca(3)-Ir(2) bond lengths are 3.14 Å. Both Ca(3)-Ir(8) bond lengths are 3.28 Å. There is one shorter (3.26 Å) and two longer (3.38 Å) Ca(3)-Ir(5) bond lengths. Both Ca(3)-As(2) bond lengths are 3.11 Å. Both Ca(3)-As(3) bond lengths are 3.10 Å. Both Ca(3)-As(7) bond lengths are 3.11 Å. In the fourth Ca site, Ca(4) is bonded in a 15-coordinate geometry to one Ir(4), one Ir(5), two equivalent Ir(2), two equivalent Ir(7), three equivalent Ir(1), two equivalent As(3), two equivalent As(4), and two equivalent As(6) atoms. The Ca(4)-Ir(4) bond length is 3.14 Å. The Ca(4)-Ir(5) bond length is 3.18 Å. Both Ca(4)-Ir(2) bond lengths are 3.23 Å. Both Ca(4)-Ir(7) bond lengths are 3.24 Å. There is one shorter (3.28 Å) and two longer (3.31 Å) Ca(4)-Ir(1) bond lengths. Both Ca(4)-As(3) bond lengths are 3.08 Å. Both Ca(4)-As(4) bond lengths are 3.10 Å. Both Ca(4)-As(6) bond lengths are 3.14 Å. There are eight inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to one Ca(1), three equivalent Ca(4), two equivalent Ir(1), two equivalent Ir(4), one As(4), and three equivalent As(6) atoms to form distorted face-sharing IrCa4As4Ir4 cuboctahedra. Both Ir(1)-Ir(1) bond lengths are 2.82 Å. Both Ir(1)-Ir(4) bond lengths are 2.85 Å. The Ir(1)-As(4) bond length is 2.48 Å. There are two shorter (2.51 Å) and one longer (2.52 Å) Ir(1)-As(6) bond length. In the second Ir site, Ir(2) is bonded in a 9-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), two equivalent Ca(4), one As(3), one As(4), and one As(7) atom. The Ir(2)-As(3) bond length is 2.43 Å. The Ir(2)-As(4) bond length is 2.36 Å. The Ir(2)-As(7) bond length is 2.41 Å. In the third Ir site, Ir(3) is bonded to one Ca(3), three equivalent Ca(2), two equivalent Ir(3), two equivalent Ir(8), one As(5), and three equivalent As(7) atoms to form distorted face-sharing IrCa4As4Ir4 cuboctahedra. Both Ir(3)-Ir(3) bond lengths are 2.90 Å. Both Ir(3)-Ir(8) bond lengths are 2.82 Å. The Ir(3)-As(5) bond length is 2.55 Å. There is one shorter (2.45 Å) and two longer (2.50 Å) Ir(3)-As(7) bond lengths. In the fourth Ir site, Ir(4) is bonded in a 7-coordinate geometry to one Ca(4), two equivalent Ca(1), two equivalent Ir(1), one As(1), one As(6), and two equivalent As(4) atoms. The Ir(4)-As(1) bond length is 2.41 Å. The Ir(4)-As(6) bond length is 2.47 Å. Both Ir(4)-As(4) bond lengths are 2.40 Å. In the fifth Ir site, Ir(5) is bonded in a 12-coordinate geometry to one Ca(4), three equivalent Ca(3), two equivalent Ir(5), two equivalent Ir(7), one As(2), and three equivalent As(3) atoms. Both Ir(5)-Ir(5) bond lengths are 2.85 Å. Both Ir(5)-Ir(7) bond lengths are 2.86 Å. The Ir(5)-As(2) bond length is 2.47 Å. There are two shorter (2.47 Å) and one longer (2.51 Å) Ir(5)-As(3) bond length. In the sixth Ir site, Ir(6) is bonded in a 4-coordinate geometry to one As(5) and three equivalent As(1) atoms. The Ir(6)-As(5) bond length is 2.40 Å. All Ir(6)-As(1) bond lengths are 2.44 Å. In the seventh Ir site, Ir(7) is bonded in a 7-coordinate geometry to one Ca(3), two equivalent Ca(4), two equivalent Ir(5), one As(3), one As(6), and two equivalent As(2) atoms. The Ir(7)-As(3) bond length is 2.49 Å. The Ir(7)-As(6) bond length is 2.40 Å. Both Ir(7)-As(2) bond lengths are 2.44 Å. In the eighth Ir site, Ir(8) is bonded in a 10-coordinate geometry to one Ca(1), one Ca(2), two equivalent Ca(3), two equivalent Ir(3), one As(2), one As(7), and two equivalent As(5) atoms. The Ir(8)-As(2) bond length is 2.42 Å. The Ir(8)-As(7) bond length is 2.48 Å. Both Ir(8)-As(5) bond lengths are 2.41 Å. There are seven inequivalent As sites. In the first As site, As(1) is bonded in a 7-coordinate geometry to one Ca(2), two equivalent Ca(1), one Ir(4), and three equivalent Ir(6) atoms. In the second As site, As(2) is bonded in a 7-coordinate geometry to one Ca(1), two equivalent Ca(3), one Ir(5), one Ir(8), and two equivalent Ir(7) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Ca(3), two equivalent Ca(4), one Ir(2), one Ir(7), and three equivalent Ir(5) atoms. In the fourth As site, As(4) is bonded in a 8-coordinate geometry to two equivalent Ca(2), two equivalent Ca(4), one Ir(1), one Ir(2), and two equivalent Ir(4) atoms. In the fifth As site, As(5) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ir(3), one Ir(6), and two equivalent Ir(8) atoms. In the sixth As site, As(6) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(4), one Ir(4), one Ir(7), and three equivalent Ir(1) atoms. In the seventh As site, As(7) is bonded in a 9-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), one Ir(2), one Ir(8), and three equivalent Ir(3) atoms.