Hf4Ni3As8 crystallizes in the tetragonal P-4m2 space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 10-coordinate geometry to two equivalent Ni(2), two equivalent As(3), two equivalent As(4), and four equivalent As(1) atoms. In the second Hf site, Hf(2) is bonded to four equivalent Ni(1,3); two equivalent As(3); two equivalent As(4); and four equivalent As(2) atoms to form a mixture of corner, face, and edge-sharing HfNi4As8 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1,3) is bonded in a 4-coordinate geometry to four equivalent Hf(2) and four equivalent As(2) atoms. In the second Ni site, Ni(2) is bonded to four equivalent Hf(1) and four equivalent As(1) atoms to form distorted edge-sharing NiHf4As4 tetrahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 6-coordinate geometry to four equivalent Hf(1) and two equivalent Ni(2) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Hf(2) and four equivalent Ni(1,3) atoms. In the third As site, As(3) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(2), and four equivalent As(4) atoms. In the fourth As site, As(4) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(2), and four equivalent As(3) atoms.
Hf4Ni3As8 crystallizes in the tetragonal P-4m2 space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 10-coordinate geometry to two equivalent Ni(2), two equivalent As(3), two equivalent As(4), and four equivalent As(1) atoms. Both Hf(1)-Ni(2) bond lengths are 2.93 Å. Both Hf(1)-As(3) bond lengths are 2.86 Å. Both Hf(1)-As(4) bond lengths are 2.86 Å. All Hf(1)-As(1) bond lengths are 2.87 Å. In the second Hf site, Hf(2) is bonded to four equivalent Ni(1,3); two equivalent As(3); two equivalent As(4); and four equivalent As(2) atoms to form a mixture of corner, face, and edge-sharing HfNi4As8 cuboctahedra. All Hf(2)-Ni(1,3) bond lengths are 2.97 Å. Both Hf(2)-As(3) bond lengths are 2.85 Å. Both Hf(2)-As(4) bond lengths are 2.85 Å. All Hf(2)-As(2) bond lengths are 2.83 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1,3) is bonded in a 4-coordinate geometry to four equivalent Hf(2) and four equivalent As(2) atoms. All Ni(1,3)-As(2) bond lengths are 2.40 Å. In the second Ni site, Ni(2) is bonded to four equivalent Hf(1) and four equivalent As(1) atoms to form distorted edge-sharing NiHf4As4 tetrahedra. All Ni(2)-As(1) bond lengths are 2.31 Å. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 6-coordinate geometry to four equivalent Hf(1) and two equivalent Ni(2) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Hf(2) and four equivalent Ni(1,3) atoms. In the third As site, As(3) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(2), and four equivalent As(4) atoms. All As(3)-As(4) bond lengths are 2.71 Å. In the fourth As site, As(4) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(2), and four equivalent As(3) atoms.