Ca6Mg2Co(AsO5)6 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(3), one O(5), one O(7), and two equivalent O(13) atoms. In the second Ca site, Ca(2) is bonded to one O(1), one O(10), one O(14), one O(15), one O(4), and one O(9) atom to form distorted CaO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra,  a cornercorner with one As(2)O4 tetrahedra, corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(3)O4 tetrahedra, and  an edgeedge with one Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-64°. In the third Ca site, Ca(3) is bonded to one O(12), one O(14), one O(15), one O(2), one O(6), and one O(8) atom to form distorted CaO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with two equivalent As(3)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra, and  an edgeedge with one Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-64°. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share  a cornercorner with one Ca(2)O6 octahedra, corners with three equivalent Ca(3)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra,  a cornercorner with one As(3)O4 tetrahedra, and corners with two equivalent As(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-64°. Co(1) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Ca(2)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-64°. There are three inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(10), one O(13), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra, and corners with two equivalent Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-61°. In the second As site, As(2) is bonded to one O(11), one O(14), one O(2), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with three equivalent Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-63°. In the third As site, As(3) is bonded to one O(12), one O(15), one O(3), and one O(9) atom to form AsO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, and corners with two equivalent Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-70°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(2), one Co(1), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ca(3), one Mg(1), and one As(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Mg(1), and one As(3) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(2) and one Mg(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ca(1) and one Co(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ca(3) and one Mg(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(1), one Mg(1), and one As(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Ca(3), one Mg(1), and one As(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(2), one Co(1), and one As(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), and one As(1) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Ca(1) and one As(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Ca(3) and one As(3) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to two equivalent Ca(1) and one As(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one As(2) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one As(3) atom.
Ca6Mg2Co(AsO5)6 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(3), one O(5), one O(7), and two equivalent O(13) atoms. The Ca(1)-O(10) bond length is 2.98 Å. The Ca(1)-O(11) bond length is 2.40 Å. The Ca(1)-O(3) bond length is 2.46 Å. The Ca(1)-O(5) bond length is 2.59 Å. The Ca(1)-O(7) bond length is 2.41 Å. There is one shorter (2.30 Å) and one longer (2.37 Å) Ca(1)-O(13) bond length. In the second Ca site, Ca(2) is bonded to one O(1), one O(10), one O(14), one O(15), one O(4), and one O(9) atom to form distorted CaO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra,  a cornercorner with one As(2)O4 tetrahedra, corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(3)O4 tetrahedra, and  an edgeedge with one Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-64°. The Ca(2)-O(1) bond length is 2.51 Å. The Ca(2)-O(10) bond length is 2.28 Å. The Ca(2)-O(14) bond length is 2.34 Å. The Ca(2)-O(15) bond length is 2.36 Å. The Ca(2)-O(4) bond length is 2.38 Å. The Ca(2)-O(9) bond length is 2.53 Å. In the third Ca site, Ca(3) is bonded to one O(12), one O(14), one O(15), one O(2), one O(6), and one O(8) atom to form distorted CaO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with two equivalent As(3)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra, and  an edgeedge with one Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-64°. The Ca(3)-O(12) bond length is 2.39 Å. The Ca(3)-O(14) bond length is 2.39 Å. The Ca(3)-O(15) bond length is 2.39 Å. The Ca(3)-O(2) bond length is 2.38 Å. The Ca(3)-O(6) bond length is 2.38 Å. The Ca(3)-O(8) bond length is 2.43 Å. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form MgO6 octahedra that share  a cornercorner with one Ca(2)O6 octahedra, corners with three equivalent Ca(3)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra,  a cornercorner with one As(3)O4 tetrahedra, and corners with two equivalent As(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 38-64°. The Mg(1)-O(2) bond length is 2.08 Å. The Mg(1)-O(3) bond length is 2.10 Å. The Mg(1)-O(4) bond length is 2.12 Å. The Mg(1)-O(6) bond length is 2.09 Å. The Mg(1)-O(7) bond length is 2.10 Å. The Mg(1)-O(8) bond length is 2.11 Å. Co(1) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Ca(2)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-64°. Both Co(1)-O(1) bond lengths are 1.95 Å. Both Co(1)-O(5) bond lengths are 1.69 Å. Both Co(1)-O(9) bond lengths are 2.01 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(10), one O(13), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra, and corners with two equivalent Ca(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-61°. The As(1)-O(1) bond length is 1.77 Å. The As(1)-O(10) bond length is 1.70 Å. The As(1)-O(13) bond length is 1.70 Å. The As(1)-O(7) bond length is 1.74 Å. In the second As site, As(2) is bonded to one O(11), one O(14), one O(2), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra, corners with two equivalent Mg(1)O6 octahedra, and corners with three equivalent Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-63°. The As(2)-O(11) bond length is 1.73 Å. The As(2)-O(14) bond length is 1.72 Å. The As(2)-O(2) bond length is 1.72 Å. The As(2)-O(8) bond length is 1.74 Å. In the third As site, As(3) is bonded to one O(12), one O(15), one O(3), and one O(9) atom to form AsO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra, corners with two equivalent Ca(2)O6 octahedra, and corners with two equivalent Ca(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-70°. The As(3)-O(12) bond length is 1.73 Å. The As(3)-O(15) bond length is 1.71 Å. The As(3)-O(3) bond length is 1.72 Å. The As(3)-O(9) bond length is 1.75 Å. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(2), one Co(1), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ca(3), one Mg(1), and one As(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Mg(1), and one As(3) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ca(2) and one Mg(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ca(1) and one Co(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ca(3) and one Mg(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(1), one Mg(1), and one As(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Ca(3), one Mg(1), and one As(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Ca(2), one Co(1), and one As(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to one Ca(1), one Ca(2), and one As(1) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Ca(1) and one As(2) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Ca(3) and one As(3) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to two equivalent Ca(1) and one As(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one As(2) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Ca(2), one Ca(3), and one As(3) atom.