ScAsO5 crystallizes in the triclinic P-1 space group. Sc(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form ScO6 octahedra that share corners with five equivalent As(1)O4 tetrahedra and  an edgeedge with one Sc(1)O6 octahedra. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with five equivalent Sc(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-57°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Sc(1) and one As(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Sc(1) and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sc(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Sc(1) and one As(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Sc(1) atom.
ScAsO5 crystallizes in the triclinic P-1 space group. Sc(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form ScO6 octahedra that share corners with five equivalent As(1)O4 tetrahedra and  an edgeedge with one Sc(1)O6 octahedra. The Sc(1)-O(2) bond length is 2.06 Å. The Sc(1)-O(3) bond length is 2.01 Å. The Sc(1)-O(4) bond length is 2.02 Å. The Sc(1)-O(5) bond length is 2.23 Å. There is one shorter (2.17 Å) and one longer (2.22 Å) Sc(1)-O(1) bond length. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with five equivalent Sc(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-57°. The As(1)-O(1) bond length is 1.75 Å. The As(1)-O(2) bond length is 1.72 Å. The As(1)-O(3) bond length is 1.71 Å. The As(1)-O(4) bond length is 1.69 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Sc(1) and one As(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Sc(1) and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sc(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Sc(1) and one As(1) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Sc(1) atom.