Ca2Mg(AsO5)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AsO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one As(1) atom. In the third O site, O(3) is bonded in a water-like geometry to one Ca(1) and one Mg(1) atom. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Mg(1), and one As(1) atom to form a mixture of distorted corner and edge-sharing OCa2MgAs tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Mg(1), and one As(1) atom.
Ca2Mg(AsO5)2 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. The Ca(1)-O(1) bond length is 2.35 Å. The Ca(1)-O(3) bond length is 2.49 Å. There is one shorter (2.30 Å) and one longer (2.43 Å) Ca(1)-O(2) bond length. There is one shorter (2.55 Å) and one longer (2.61 Å) Ca(1)-O(4) bond length. There is one shorter (2.55 Å) and one longer (2.72 Å) Ca(1)-O(5) bond length. Mg(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra. Both Mg(1)-O(3) bond lengths are 2.15 Å. Both Mg(1)-O(4) bond lengths are 2.17 Å. Both Mg(1)-O(5) bond lengths are 2.08 Å. As(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AsO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. The As(1)-O(1) bond length is 1.74 Å. The As(1)-O(2) bond length is 1.70 Å. The As(1)-O(4) bond length is 1.73 Å. The As(1)-O(5) bond length is 1.73 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ca(1) and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one As(1) atom. In the third O site, O(3) is bonded in a water-like geometry to one Ca(1) and one Mg(1) atom. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Mg(1), and one As(1) atom to form a mixture of distorted corner and edge-sharing OCa2MgAs tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Mg(1), and one As(1) atom.