CsScAs2(HO4)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 14-coordinate geometry to two equivalent H(2), two equivalent O(1), two equivalent O(12), two equivalent O(2), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(6), one O(7), one O(8), and one O(9) atom. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to two equivalent O(4), two equivalent O(6), and two equivalent O(9) atoms to form ScO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. In the second Sc site, Sc(2) is bonded to one O(1), one O(10), one O(11), one O(3), one O(5), and one O(7) atom to form ScO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. There are three inequivalent As sites. In the first As site, 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  a cornercorner with one Sc(1)O6 octahedra and corners with two equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-49°. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Sc(1)O6 octahedra and corners with two equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-56°. In the third As site, As(3) is bonded to one O(10), one O(11), one O(12), and one O(9) atom to form AsO4 tetrahedra that share  a cornercorner with one Sc(1)O6 octahedra and corners with two equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-52°. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(2) atom. In the second H site, H(2) is bonded in a distorted linear geometry to one Cs(1), one O(10), and one O(8) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(12) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Cs(1), one Sc(2), and one As(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Cs(2), one As(1), and one H(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Cs(2), one Sc(2), and one As(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Sc(1) and one As(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Cs(1), one Sc(2), and one As(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cs(2), one Sc(1), and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cs(1), one Cs(2), one Sc(2), and one As(2) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Cs(1), one Cs(2), one As(2), and one H(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Cs(2), one Sc(1), and one As(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Cs(2), one Sc(2), one As(3), and one H(2) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Sc(2) and one As(3) atom. In the twelfth O site, O(12) is bonded in a distorted water-like geometry to one Cs(1), one Cs(2), one As(3), and one H(3) atom.
CsScAs2(HO4)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 14-coordinate geometry to two equivalent H(2), two equivalent O(1), two equivalent O(12), two equivalent O(2), two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. Both Cs(1)-H(2) bond lengths are 3.34 Å. Both Cs(1)-O(1) bond lengths are 3.06 Å. Both Cs(1)-O(12) bond lengths are 3.78 Å. Both Cs(1)-O(2) bond lengths are 3.39 Å. Both Cs(1)-O(5) bond lengths are 3.73 Å. Both Cs(1)-O(7) bond lengths are 3.54 Å. Both Cs(1)-O(8) bond lengths are 3.29 Å. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(2), one O(3), one O(6), one O(7), one O(8), and one O(9) atom. The Cs(2)-O(10) bond length is 3.58 Å. The Cs(2)-O(12) bond length is 3.23 Å. The Cs(2)-O(2) bond length is 3.16 Å. The Cs(2)-O(3) bond length is 3.05 Å. The Cs(2)-O(6) bond length is 3.41 Å. The Cs(2)-O(7) bond length is 3.65 Å. The Cs(2)-O(8) bond length is 3.19 Å. The Cs(2)-O(9) bond length is 3.48 Å. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to two equivalent O(4), two equivalent O(6), and two equivalent O(9) atoms to form ScO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. Both Sc(1)-O(4) bond lengths are 2.06 Å. Both Sc(1)-O(6) bond lengths are 2.13 Å. Both Sc(1)-O(9) bond lengths are 2.21 Å. In the second Sc site, Sc(2) is bonded to one O(1), one O(10), one O(11), one O(3), one O(5), and one O(7) atom to form ScO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. The Sc(2)-O(1) bond length is 2.08 Å. The Sc(2)-O(10) bond length is 2.14 Å. The Sc(2)-O(11) bond length is 2.07 Å. The Sc(2)-O(3) bond length is 2.19 Å. The Sc(2)-O(5) bond length is 2.06 Å. The Sc(2)-O(7) bond length is 2.14 Å. There are three inequivalent As sites. In the first As site, 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  a cornercorner with one Sc(1)O6 octahedra and corners with two equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-49°. The As(1)-O(1) bond length is 1.70 Å. The As(1)-O(2) bond length is 1.78 Å. The As(1)-O(3) bond length is 1.72 Å. The As(1)-O(4) bond length is 1.70 Å. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Sc(1)O6 octahedra and corners with two equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-56°. The As(2)-O(5) bond length is 1.70 Å. The As(2)-O(6) bond length is 1.70 Å. The As(2)-O(7) bond length is 1.72 Å. The As(2)-O(8) bond length is 1.79 Å. In the third As site, As(3) is bonded to one O(10), one O(11), one O(12), and one O(9) atom to form AsO4 tetrahedra that share  a cornercorner with one Sc(1)O6 octahedra and corners with two equivalent Sc(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-52°. The As(3)-O(10) bond length is 1.71 Å. The As(3)-O(11) bond length is 1.69 Å. The As(3)-O(12) bond length is 1.78 Å. The As(3)-O(9) bond length is 1.71 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(2) atom. The H(1)-O(2) bond length is 1.00 Å. In the second H site, H(2) is bonded in a distorted linear geometry to one Cs(1), one O(10), and one O(8) atom. The H(2)-O(10) bond length is 1.66 Å. The H(2)-O(8) bond length is 1.01 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(12) atom. The H(3)-O(12) bond length is 1.01 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Cs(1), one Sc(2), and one As(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Cs(2), one As(1), and one H(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Cs(2), one Sc(2), and one As(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Sc(1) and one As(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Cs(1), one Sc(2), and one As(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cs(2), one Sc(1), and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cs(1), one Cs(2), one Sc(2), and one As(2) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Cs(1), one Cs(2), one As(2), and one H(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Cs(2), one Sc(1), and one As(3) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Cs(2), one Sc(2), one As(3), and one H(2) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Sc(2) and one As(3) atom. In the twelfth O site, O(12) is bonded in a distorted water-like geometry to one Cs(1), one Cs(2), one As(3), and one H(3) atom.