Sc5As3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 5-coordinate geometry to two equivalent As(1) and three equivalent As(2) atoms. In the second Sc site, Sc(2) is bonded in a 5-coordinate geometry to two equivalent As(1) and four equivalent As(2) atoms. In the third Sc site, Sc(3) is bonded to one As(1) and four equivalent As(2) atoms to form distorted edge-sharing ScAs5 square pyramids. In the fourth Sc site, Sc(4) is bonded in a 5-coordinate geometry to one As(1) and four equivalent As(2) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Sc(3), one Sc(4), two equivalent Sc(2), and four equivalent Sc(1) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Sc(2), two equivalent Sc(3), two equivalent Sc(4), and three equivalent Sc(1) atoms.
Sc5As3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 5-coordinate geometry to two equivalent As(1) and three equivalent As(2) atoms. There is one shorter (2.65 Å) and one longer (2.73 Å) Sc(1)-As(1) bond length. There are a spread of Sc(1)-As(2) bond distances ranging from 2.93-3.20 Å. In the second Sc site, Sc(2) is bonded in a 5-coordinate geometry to two equivalent As(1) and four equivalent As(2) atoms. There is one shorter (2.66 Å) and one longer (3.33 Å) Sc(2)-As(1) bond length. There are two shorter (2.81 Å) and two longer (2.94 Å) Sc(2)-As(2) bond lengths. In the third Sc site, Sc(3) is bonded to one As(1) and four equivalent As(2) atoms to form distorted edge-sharing ScAs5 square pyramids. The Sc(3)-As(1) bond length is 2.82 Å. There are two shorter (2.80 Å) and two longer (2.81 Å) Sc(3)-As(2) bond lengths. In the fourth Sc site, Sc(4) is bonded in a 5-coordinate geometry to one As(1) and four equivalent As(2) atoms. The Sc(4)-As(1) bond length is 2.64 Å. There are two shorter (2.88 Å) and two longer (2.93 Å) Sc(4)-As(2) bond lengths. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one Sc(3), one Sc(4), two equivalent Sc(2), and four equivalent Sc(1) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Sc(2), two equivalent Sc(3), two equivalent Sc(4), and three equivalent Sc(1) atoms.