Sc7As3 crystallizes in the tetragonal I4/mcm space group. There are five inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 4-coordinate geometry to one Sc(5), two equivalent As(1), and two equivalent As(2) atoms. In the second Sc site, Sc(2) is bonded to one As(2) and four equivalent As(1) atoms to form a mixture of distorted corner and edge-sharing ScAs5 trigonal bipyramids. In the third Sc site, Sc(3) is bonded in a 3-coordinate geometry to two equivalent Sc(5), one As(2), and two equivalent As(1) atoms. In the fourth Sc site, Sc(4) is bonded in a square co-planar geometry to four equivalent As(1) atoms. In the fifth Sc site, Sc(5) is bonded in a 12-coordinate geometry to four equivalent Sc(1) and eight equivalent Sc(3) atoms. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Sc(2), two equivalent Sc(3), and four equivalent Sc(1) atoms. In the second As site, As(1) is bonded in a 9-coordinate geometry to one Sc(4), two equivalent Sc(1), two equivalent Sc(3), and four equivalent Sc(2) atoms.
Sc7As3 crystallizes in the tetragonal I4/mcm space group. There are five inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 4-coordinate geometry to one Sc(5), two equivalent As(1), and two equivalent As(2) atoms. The Sc(1)-Sc(5) bond length is 3.46 Å. Both Sc(1)-As(1) bond lengths are 3.17 Å. There is one shorter (2.67 Å) and one longer (2.77 Å) Sc(1)-As(2) bond length. In the second Sc site, Sc(2) is bonded to one As(2) and four equivalent As(1) atoms to form a mixture of distorted corner and edge-sharing ScAs5 trigonal bipyramids. The Sc(2)-As(2) bond length is 2.70 Å. There are two shorter (2.83 Å) and two longer (2.91 Å) Sc(2)-As(1) bond lengths. In the third Sc site, Sc(3) is bonded in a 3-coordinate geometry to two equivalent Sc(5), one As(2), and two equivalent As(1) atoms. Both Sc(3)-Sc(5) bond lengths are 3.21 Å. The Sc(3)-As(2) bond length is 2.99 Å. Both Sc(3)-As(1) bond lengths are 2.80 Å. In the fourth Sc site, Sc(4) is bonded in a square co-planar geometry to four equivalent As(1) atoms. All Sc(4)-As(1) bond lengths are 2.81 Å. In the fifth Sc site, Sc(5) is bonded in a 12-coordinate geometry to four equivalent Sc(1) and eight equivalent Sc(3) atoms. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Sc(2), two equivalent Sc(3), and four equivalent Sc(1) atoms. In the second As site, As(1) is bonded in a 9-coordinate geometry to one Sc(4), two equivalent Sc(1), two equivalent Sc(3), and four equivalent Sc(2) atoms.