ScNiSi3 crystallizes in the orthorhombic Cmmm space group. Sc(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), two equivalent Si(2), two equivalent Si(3), and six equivalent Si(1) atoms. Ni(1) is bonded in a 9-coordinate geometry to four equivalent Sc(1), one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Sc(1), one Ni(1), and two equivalent Si(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Ni(1), one Si(2), and four equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Ni(1), one Si(3), and four equivalent Si(2) atoms.
ScNiSi3 crystallizes in the orthorhombic Cmmm space group. Sc(1) is bonded in a 14-coordinate geometry to four equivalent Ni(1), two equivalent Si(2), two equivalent Si(3), and six equivalent Si(1) atoms. All Sc(1)-Ni(1) bond lengths are 2.95 Å. Both Sc(1)-Si(2) bond lengths are 3.00 Å. Both Sc(1)-Si(3) bond lengths are 3.00 Å. There are four shorter (2.89 Å) and two longer (3.01 Å) Sc(1)-Si(1) bond lengths. Ni(1) is bonded in a 9-coordinate geometry to four equivalent Sc(1), one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. The Ni(1)-Si(1) bond length is 2.18 Å. Both Ni(1)-Si(2) bond lengths are 2.23 Å. Both Ni(1)-Si(3) bond lengths are 2.23 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Sc(1), one Ni(1), and two equivalent Si(1) atoms. Both Si(1)-Si(1) bond lengths are 2.33 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Ni(1), one Si(2), and four equivalent Si(3) atoms. The Si(2)-Si(2) bond length is 2.35 Å. All Si(2)-Si(3) bond lengths are 2.71 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Sc(1), two equivalent Ni(1), one Si(3), and four equivalent Si(2) atoms. The Si(3)-Si(3) bond length is 2.35 Å.