Sc3Ni11Si4 crystallizes in the hexagonal P6_3/mmc space group. Sc(1) is bonded in a 15-coordinate geometry to two equivalent Ni(2), two equivalent Ni(3), six equivalent Ni(1), one Si(1), and four equivalent Si(2) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to three equivalent Sc(1), one Ni(3), two equivalent Ni(2), three equivalent Ni(1), one Si(1), and two equivalent Si(2) atoms. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to two equivalent Sc(1), two equivalent Ni(2), two equivalent Ni(3), four equivalent Ni(1), and two equivalent Si(2) atoms. In the third Ni site, Ni(3) is bonded in a 12-coordinate geometry to three equivalent Sc(1), three equivalent Ni(1), three equivalent Ni(2), and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Sc(1) and six equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded to four equivalent Sc(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(1) atoms to form a mixture of face and corner-sharing SiSc4Ni8 cuboctahedra.
Sc3Ni11Si4 crystallizes in the hexagonal P6_3/mmc space group. Sc(1) is bonded in a 15-coordinate geometry to two equivalent Ni(2), two equivalent Ni(3), six equivalent Ni(1), one Si(1), and four equivalent Si(2) atoms. Both Sc(1)-Ni(2) bond lengths are 2.73 Å. Both Sc(1)-Ni(3) bond lengths are 2.77 Å. There are four shorter (2.79 Å) and two longer (2.92 Å) Sc(1)-Ni(1) bond lengths. The Sc(1)-Si(1) bond length is 2.72 Å. All Sc(1)-Si(2) bond lengths are 2.96 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to three equivalent Sc(1), one Ni(3), two equivalent Ni(2), three equivalent Ni(1), one Si(1), and two equivalent Si(2) atoms. The Ni(1)-Ni(3) bond length is 2.61 Å. Both Ni(1)-Ni(2) bond lengths are 2.53 Å. There are two shorter (2.60 Å) and one longer (2.62 Å) Ni(1)-Ni(1) bond length. The Ni(1)-Si(1) bond length is 2.47 Å. Both Ni(1)-Si(2) bond lengths are 2.52 Å. In the second Ni site, Ni(2) is bonded in a 12-coordinate geometry to two equivalent Sc(1), two equivalent Ni(2), two equivalent Ni(3), four equivalent Ni(1), and two equivalent Si(2) atoms. Both Ni(2)-Ni(2) bond lengths are 2.51 Å. Both Ni(2)-Ni(3) bond lengths are 2.56 Å. Both Ni(2)-Si(2) bond lengths are 2.24 Å. In the third Ni site, Ni(3) is bonded in a 12-coordinate geometry to three equivalent Sc(1), three equivalent Ni(1), three equivalent Ni(2), and three equivalent Si(2) atoms. All Ni(3)-Si(2) bond lengths are 2.29 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Sc(1) and six equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded to four equivalent Sc(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(1) atoms to form a mixture of face and corner-sharing SiSc4Ni8 cuboctahedra.