Ca5Ni9As7 crystallizes in the hexagonal P-6 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to one Ni(3), two equivalent Ni(1), four equivalent Ni(2), one As(1), two equivalent As(2), and two equivalent As(3) atoms. In the second Ca site, Ca(2) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent As(1) atoms. In the third Ca site, Ca(3) is bonded in a 15-coordinate geometry to three equivalent Ni(3), six equivalent Ni(1), and six equivalent As(3) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 1-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Ca(3), one Ni(2), two equivalent As(1), and two equivalent As(3) atoms. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to one Ca(2), four equivalent Ca(1), one Ni(1), two equivalent Ni(3), one As(2), one As(3), and two equivalent As(1) atoms. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), two equivalent Ca(2), two equivalent Ni(2), two equivalent As(1), and two equivalent As(3) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to one Ca(1), two equivalent Ca(2), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Ni(3) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three equivalent Ni(2) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(3), one Ni(2), two equivalent Ni(1), and two equivalent Ni(3) atoms.
Ca5Ni9As7 crystallizes in the hexagonal P-6 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to one Ni(3), two equivalent Ni(1), four equivalent Ni(2), one As(1), two equivalent As(2), and two equivalent As(3) atoms. The Ca(1)-Ni(3) bond length is 2.94 Å. Both Ca(1)-Ni(1) bond lengths are 3.03 Å. There are two shorter (3.04 Å) and two longer (3.18 Å) Ca(1)-Ni(2) bond lengths. The Ca(1)-As(1) bond length is 2.81 Å. Both Ca(1)-As(2) bond lengths are 2.83 Å. Both Ca(1)-As(3) bond lengths are 2.86 Å. In the second Ca site, Ca(2) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent As(1) atoms. All Ca(2)-Ni(1) bond lengths are 3.42 Å. All Ca(2)-Ni(2) bond lengths are 3.13 Å. All Ca(2)-Ni(3) bond lengths are 3.21 Å. All Ca(2)-As(1) bond lengths are 2.97 Å. In the third Ca site, Ca(3) is bonded in a 15-coordinate geometry to three equivalent Ni(3), six equivalent Ni(1), and six equivalent As(3) atoms. All Ca(3)-Ni(3) bond lengths are 3.44 Å. All Ca(3)-Ni(1) bond lengths are 3.35 Å. All Ca(3)-As(3) bond lengths are 3.11 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 1-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Ca(3), one Ni(2), two equivalent As(1), and two equivalent As(3) atoms. The Ni(1)-Ni(2) bond length is 2.58 Å. Both Ni(1)-As(1) bond lengths are 2.60 Å. There is one shorter (2.29 Å) and one longer (2.80 Å) Ni(1)-As(3) bond length. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to one Ca(2), four equivalent Ca(1), one Ni(1), two equivalent Ni(3), one As(2), one As(3), and two equivalent As(1) atoms. Both Ni(2)-Ni(3) bond lengths are 2.81 Å. The Ni(2)-As(2) bond length is 2.63 Å. The Ni(2)-As(3) bond length is 2.42 Å. Both Ni(2)-As(1) bond lengths are 2.42 Å. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(3), two equivalent Ca(2), two equivalent Ni(2), two equivalent As(1), and two equivalent As(3) atoms. There is one shorter (2.32 Å) and one longer (2.42 Å) Ni(3)-As(1) bond length. Both Ni(3)-As(3) bond lengths are 2.44 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to one Ca(1), two equivalent Ca(2), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Ni(3) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three equivalent Ni(2) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(3), one Ni(2), two equivalent Ni(1), and two equivalent Ni(3) atoms.