Rh3NiAs2 crystallizes in the orthorhombic Pmc2_1 space group. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a 3-coordinate geometry to one As(2) and four equivalent As(1) atoms. In the second Rh site, Rh(2) is bonded in a 4-coordinate geometry to two equivalent Ni(1), two equivalent As(1), and two equivalent As(2) atoms. In the third Rh site, Rh(3) is bonded in a 8-coordinate geometry to four equivalent Ni(1), two equivalent As(1), and two equivalent As(2) atoms. Ni(1) is bonded in a 11-coordinate geometry to two equivalent Rh(2), four equivalent Rh(3), one As(1), and four equivalent As(2) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Rh(2), two equivalent Rh(3), four equivalent Rh(1), and one Ni(1) atom. In the second As site, As(2) is bonded in a 9-coordinate geometry to one Rh(1), two equivalent Rh(2), two equivalent Rh(3), and four equivalent Ni(1) atoms.
Rh3NiAs2 crystallizes in the orthorhombic Pmc2_1 space group. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a 3-coordinate geometry to one As(2) and four equivalent As(1) atoms. The Rh(1)-As(2) bond length is 2.47 Å. There are two shorter (2.53 Å) and two longer (2.91 Å) Rh(1)-As(1) bond lengths. In the second Rh site, Rh(2) is bonded in a 4-coordinate geometry to two equivalent Ni(1), two equivalent As(1), and two equivalent As(2) atoms. There is one shorter (2.92 Å) and one longer (2.98 Å) Rh(2)-Ni(1) bond length. There is one shorter (2.46 Å) and one longer (2.48 Å) Rh(2)-As(1) bond length. Both Rh(2)-As(2) bond lengths are 2.49 Å. In the third Rh site, Rh(3) is bonded in a 8-coordinate geometry to four equivalent Ni(1), two equivalent As(1), and two equivalent As(2) atoms. There are two shorter (2.78 Å) and two longer (2.89 Å) Rh(3)-Ni(1) bond lengths. Both Rh(3)-As(1) bond lengths are 2.52 Å. There is one shorter (2.37 Å) and one longer (2.45 Å) Rh(3)-As(2) bond length. Ni(1) is bonded in a 11-coordinate geometry to two equivalent Rh(2), four equivalent Rh(3), one As(1), and four equivalent As(2) atoms. The Ni(1)-As(1) bond length is 2.43 Å. There are two shorter (2.57 Å) and two longer (2.86 Å) Ni(1)-As(2) bond lengths. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Rh(2), two equivalent Rh(3), four equivalent Rh(1), and one Ni(1) atom. In the second As site, As(2) is bonded in a 9-coordinate geometry to one Rh(1), two equivalent Rh(2), two equivalent Rh(3), and four equivalent Ni(1) atoms.