Er5Zr3(Ni4As3)4 crystallizes in the hexagonal P-62m space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 16-coordinate geometry to two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(4), four equivalent Ni(3), two equivalent As(2), and four equivalent As(1) atoms. In the second Er site, Er(2) is bonded in a 15-coordinate geometry to three equivalent Ni(3), six equivalent Ni(1), and six equivalent As(3) atoms. Zr(1) is bonded in a 13-coordinate geometry to two equivalent Ni(2), two equivalent Ni(3), four equivalent Ni(1), one As(2), and four equivalent As(3) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to one Er(1), two equivalent Er(2), two equivalent Zr(1), two equivalent As(2), and two equivalent As(3) atoms. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to two equivalent Er(1), two equivalent Zr(1), two equivalent As(1), and two equivalent As(3) atoms. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to one Er(2), two equivalent Er(1), one Zr(1), one As(1), one As(2), and two equivalent As(3) atoms. In the fourth Ni site, Ni(4) is bonded in a distorted trigonal planar geometry to six equivalent Er(1) and three equivalent As(1) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to four equivalent Er(1), one Ni(4), 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 two equivalent Er(1), one Zr(1), two equivalent Ni(3), and four equivalent Ni(1) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Er(2), two equivalent Zr(1), one Ni(2), two equivalent Ni(1), and two equivalent Ni(3) atoms.
Er5Zr3(Ni4As3)4 crystallizes in the hexagonal P-62m space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 16-coordinate geometry to two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(4), four equivalent Ni(3), two equivalent As(2), and four equivalent As(1) atoms. Both Er(1)-Ni(1) bond lengths are 3.32 Å. Both Er(1)-Ni(2) bond lengths are 3.10 Å. Both Er(1)-Ni(4) bond lengths are 3.05 Å. All Er(1)-Ni(3) bond lengths are 3.14 Å. Both Er(1)-As(2) bond lengths are 2.93 Å. All Er(1)-As(1) bond lengths are 3.02 Å. In the second Er site, Er(2) is bonded in a 15-coordinate geometry to three equivalent Ni(3), six equivalent Ni(1), and six equivalent As(3) atoms. All Er(2)-Ni(3) bond lengths are 3.21 Å. All Er(2)-Ni(1) bond lengths are 3.21 Å. All Er(2)-As(3) bond lengths are 2.97 Å. Zr(1) is bonded in a 13-coordinate geometry to two equivalent Ni(2), two equivalent Ni(3), four equivalent Ni(1), one As(2), and four equivalent As(3) atoms. Both Zr(1)-Ni(2) bond lengths are 2.84 Å. Both Zr(1)-Ni(3) bond lengths are 2.81 Å. All Zr(1)-Ni(1) bond lengths are 2.97 Å. The Zr(1)-As(2) bond length is 2.65 Å. All Zr(1)-As(3) bond lengths are 2.79 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 4-coordinate geometry to one Er(1), two equivalent Er(2), two equivalent Zr(1), two equivalent As(2), and two equivalent As(3) atoms. Both Ni(1)-As(2) bond lengths are 2.52 Å. There is one shorter (2.39 Å) and one longer (2.42 Å) Ni(1)-As(3) bond length. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to two equivalent Er(1), two equivalent Zr(1), two equivalent As(1), and two equivalent As(3) atoms. Both Ni(2)-As(1) bond lengths are 2.32 Å. Both Ni(2)-As(3) bond lengths are 2.43 Å. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to one Er(2), two equivalent Er(1), one Zr(1), one As(1), one As(2), and two equivalent As(3) atoms. The Ni(3)-As(1) bond length is 2.44 Å. The Ni(3)-As(2) bond length is 2.33 Å. Both Ni(3)-As(3) bond lengths are 2.40 Å. In the fourth Ni site, Ni(4) is bonded in a distorted trigonal planar geometry to six equivalent Er(1) and three equivalent As(1) atoms. All Ni(4)-As(1) bond lengths are 2.26 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to four equivalent Er(1), one Ni(4), 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 two equivalent Er(1), one Zr(1), two equivalent Ni(3), and four equivalent Ni(1) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Er(2), two equivalent Zr(1), one Ni(2), two equivalent Ni(1), and two equivalent Ni(3) atoms.