Sc3(NiSi)4 crystallizes in the orthorhombic Immm space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to eight equivalent Ni(1), two equivalent Si(1), and four equivalent Si(2) atoms to form distorted face-sharing ScSi6Ni8 octahedra. In the second Sc site, Sc(2) is bonded in a 12-coordinate geometry to six equivalent Ni(1), two equivalent Si(1), and four equivalent Si(2) atoms. Ni(1) is bonded in a 12-coordinate geometry to two equivalent Sc(1), three equivalent Sc(2), three equivalent Ni(1), one Si(2), and three equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Sc(1), two equivalent Sc(2), and six equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), four equivalent Sc(2), two equivalent Ni(1), and one Si(2) atom.
Sc3(NiSi)4 crystallizes in the orthorhombic Immm space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to eight equivalent Ni(1), two equivalent Si(1), and four equivalent Si(2) atoms to form distorted face-sharing ScSi6Ni8 octahedra. All Sc(1)-Ni(1) bond lengths are 3.21 Å. Both Sc(1)-Si(1) bond lengths are 2.79 Å. All Sc(1)-Si(2) bond lengths are 2.80 Å. In the second Sc site, Sc(2) is bonded in a 12-coordinate geometry to six equivalent Ni(1), two equivalent Si(1), and four equivalent Si(2) atoms. All Sc(2)-Ni(1) bond lengths are 2.82 Å. Both Sc(2)-Si(1) bond lengths are 2.74 Å. All Sc(2)-Si(2) bond lengths are 2.79 Å. Ni(1) is bonded in a 12-coordinate geometry to two equivalent Sc(1), three equivalent Sc(2), three equivalent Ni(1), one Si(2), and three equivalent Si(1) atoms. There is one shorter (2.54 Å) and two longer (2.80 Å) Ni(1)-Ni(1) bond lengths. The Ni(1)-Si(2) bond length is 2.34 Å. All Ni(1)-Si(1) bond lengths are 2.38 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Sc(1), two equivalent Sc(2), and six equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), four equivalent Sc(2), two equivalent Ni(1), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.43 Å.