Sc2(NbSi)3 crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Sc site, Sc(2) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(4) atoms. In the third Sc site, Sc(3) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(1), and two equivalent Si(4) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(2), and two equivalent Si(4) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), and two equivalent Si(4) atoms. There are four 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), two equivalent Sc(3), and four equivalent Nb(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Sc(1), two equivalent Sc(2), two equivalent Nb(1), and four equivalent Nb(2) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Sc(3), two equivalent Sc(1), two equivalent Nb(1), and four equivalent Nb(2) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Sc(3), two equivalent Sc(2), two equivalent Nb(1), and four equivalent Nb(2) atoms.
Sc2(NbSi)3 crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. The Sc(1)-Si(1) bond length is 2.77 Å. Both Sc(1)-Si(2) bond lengths are 2.68 Å. Both Sc(1)-Si(3) bond lengths are 2.90 Å. In the second Sc site, Sc(2) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(4) atoms. The Sc(2)-Si(1) bond length is 2.69 Å. There is one shorter (2.67 Å) and one longer (2.76 Å) Sc(2)-Si(2) bond length. Both Sc(2)-Si(4) bond lengths are 2.90 Å. In the third Sc site, Sc(3) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(1), and two equivalent Si(4) atoms. The Sc(3)-Si(3) bond length is 2.79 Å. Both Sc(3)-Si(1) bond lengths are 2.91 Å. Both Sc(3)-Si(4) bond lengths are 2.68 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(2), and two equivalent Si(4) atoms. The Nb(1)-Si(3) bond length is 2.66 Å. Both Nb(1)-Si(2) bond lengths are 2.87 Å. There is one shorter (2.67 Å) and one longer (2.68 Å) Nb(1)-Si(4) bond length. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), and two equivalent Si(4) atoms. The Nb(2)-Si(1) bond length is 2.74 Å. The Nb(2)-Si(3) bond length is 2.76 Å. There is one shorter (2.72 Å) and one longer (2.74 Å) Nb(2)-Si(2) bond length. There is one shorter (2.74 Å) and one longer (2.75 Å) Nb(2)-Si(4) bond length. There are four 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), two equivalent Sc(3), and four equivalent Nb(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Sc(1), two equivalent Sc(2), two equivalent Nb(1), and four equivalent Nb(2) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Sc(3), two equivalent Sc(1), two equivalent Nb(1), and four equivalent Nb(2) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Sc(3), two equivalent Sc(2), two equivalent Nb(1), and four equivalent Nb(2) atoms.