Ca2VAlO5 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(5), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(4), one O(7), one O(8), one O(9), and two equivalent O(6) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(6), one O(7), one O(8), one O(9), and two equivalent O(4) atoms. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(7), one O(8), one O(9), and two equivalent O(5) atoms. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(10), one O(3), one O(4), one O(7), one O(8), and one O(9) atom to form VO6 octahedra that share corners with four equivalent V(2)O6 octahedra,  a cornercorner with one Al(1)O4 tetrahedra, and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-14°. In the second V site, V(2) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form VO6 octahedra that share corners with four equivalent V(1)O6 octahedra,  a cornercorner with one Al(1)O4 tetrahedra, and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-14°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AlO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, and corners with two equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-44°. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-44°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Ca(3), one Ca(4), one Al(1), and one Al(2) atom to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(10)Ca4V2 octahedra, corners with two equivalent O(7)Ca4V2 octahedra, corners with two equivalent O(8)Ca4V2 octahedra, corners with two equivalent O(9)Ca4V2 octahedra, and corners with two equivalent O(2)Ca2Al2 tetrahedra. The corner-sharing octahedral tilt angles range from 14-90°. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), one Al(1), and one Al(2) atom to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(10)Ca4V2 octahedra, corners with two equivalent O(7)Ca4V2 octahedra, corners with two equivalent O(8)Ca4V2 octahedra, corners with two equivalent O(9)Ca4V2 octahedra, and corners with two equivalent O(1)Ca2Al2 tetrahedra. The corner-sharing octahedral tilt angles range from 13-90°. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(4), two equivalent Ca(1), one V(1), and one Al(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(3), one V(1), and one Al(1) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(4), one V(2), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(2), one V(2), and one Al(2) atom. In the seventh O site, O(7) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(9)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(9)Ca4V2 octahedra, faces with two equivalent O(10)Ca4V2 octahedra, and faces with two equivalent O(8)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the eighth O site, O(8) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(10)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(10)Ca4V2 octahedra, faces with two equivalent O(7)Ca4V2 octahedra, and faces with two equivalent O(9)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the ninth O site, O(9) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(7)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(7)Ca4V2 octahedra, faces with two equivalent O(10)Ca4V2 octahedra, and faces with two equivalent O(8)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the tenth O site, O(10) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(8)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(8)Ca4V2 octahedra, faces with two equivalent O(7)Ca4V2 octahedra, and faces with two equivalent O(9)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°.
Ca2VAlO5 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(5), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. The Ca(1)-O(10) bond length is 2.61 Å. The Ca(1)-O(2) bond length is 2.39 Å. The Ca(1)-O(5) bond length is 2.31 Å. The Ca(1)-O(7) bond length is 2.57 Å. The Ca(1)-O(8) bond length is 2.49 Å. The Ca(1)-O(9) bond length is 2.54 Å. There is one shorter (2.58 Å) and one longer (2.97 Å) Ca(1)-O(3) bond length. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), one O(4), one O(7), one O(8), one O(9), and two equivalent O(6) atoms. The Ca(2)-O(10) bond length is 2.50 Å. The Ca(2)-O(2) bond length is 2.39 Å. The Ca(2)-O(4) bond length is 2.31 Å. The Ca(2)-O(7) bond length is 2.52 Å. The Ca(2)-O(8) bond length is 2.63 Å. The Ca(2)-O(9) bond length is 2.56 Å. There is one shorter (2.57 Å) and one longer (2.98 Å) Ca(2)-O(6) bond length. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(6), one O(7), one O(8), one O(9), and two equivalent O(4) atoms. The Ca(3)-O(1) bond length is 2.39 Å. The Ca(3)-O(10) bond length is 2.53 Å. The Ca(3)-O(6) bond length is 2.31 Å. The Ca(3)-O(7) bond length is 2.50 Å. The Ca(3)-O(8) bond length is 2.57 Å. The Ca(3)-O(9) bond length is 2.60 Å. There is one shorter (2.58 Å) and one longer (2.97 Å) Ca(3)-O(4) bond length. In the fourth Ca site, Ca(4) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(7), one O(8), one O(9), and two equivalent O(5) atoms. The Ca(4)-O(1) bond length is 2.39 Å. The Ca(4)-O(10) bond length is 2.58 Å. The Ca(4)-O(3) bond length is 2.31 Å. The Ca(4)-O(7) bond length is 2.60 Å. The Ca(4)-O(8) bond length is 2.54 Å. The Ca(4)-O(9) bond length is 2.48 Å. There is one shorter (2.58 Å) and one longer (2.96 Å) Ca(4)-O(5) bond length. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(10), one O(3), one O(4), one O(7), one O(8), and one O(9) atom to form VO6 octahedra that share corners with four equivalent V(2)O6 octahedra,  a cornercorner with one Al(1)O4 tetrahedra, and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-14°. The V(1)-O(10) bond length is 1.97 Å. The V(1)-O(3) bond length is 2.16 Å. The V(1)-O(4) bond length is 2.16 Å. The V(1)-O(7) bond length is 1.99 Å. The V(1)-O(8) bond length is 1.97 Å. The V(1)-O(9) bond length is 1.99 Å. In the second V site, V(2) is bonded to one O(10), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form VO6 octahedra that share corners with four equivalent V(1)O6 octahedra,  a cornercorner with one Al(1)O4 tetrahedra, and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-14°. The V(2)-O(10) bond length is 1.98 Å. The V(2)-O(5) bond length is 2.16 Å. The V(2)-O(6) bond length is 2.16 Å. The V(2)-O(7) bond length is 1.99 Å. The V(2)-O(8) bond length is 1.97 Å. The V(2)-O(9) bond length is 1.99 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AlO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, and corners with two equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-44°. The Al(1)-O(1) bond length is 1.83 Å. The Al(1)-O(2) bond length is 1.82 Å. The Al(1)-O(4) bond length is 1.76 Å. The Al(1)-O(5) bond length is 1.76 Å. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one V(1)O6 octahedra,  a cornercorner with one V(2)O6 octahedra, and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 43-44°. The Al(2)-O(1) bond length is 1.82 Å. The Al(2)-O(2) bond length is 1.83 Å. The Al(2)-O(3) bond length is 1.76 Å. The Al(2)-O(6) bond length is 1.76 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Ca(3), one Ca(4), one Al(1), and one Al(2) atom to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(10)Ca4V2 octahedra, corners with two equivalent O(7)Ca4V2 octahedra, corners with two equivalent O(8)Ca4V2 octahedra, corners with two equivalent O(9)Ca4V2 octahedra, and corners with two equivalent O(2)Ca2Al2 tetrahedra. The corner-sharing octahedral tilt angles range from 14-90°. In the second O site, O(2) is bonded to one Ca(1), one Ca(2), one Al(1), and one Al(2) atom to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(10)Ca4V2 octahedra, corners with two equivalent O(7)Ca4V2 octahedra, corners with two equivalent O(8)Ca4V2 octahedra, corners with two equivalent O(9)Ca4V2 octahedra, and corners with two equivalent O(1)Ca2Al2 tetrahedra. The corner-sharing octahedral tilt angles range from 13-90°. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(4), two equivalent Ca(1), one V(1), and one Al(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(3), one V(1), and one Al(1) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(4), one V(2), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(2), one V(2), and one Al(2) atom. In the seventh O site, O(7) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(9)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(9)Ca4V2 octahedra, faces with two equivalent O(10)Ca4V2 octahedra, and faces with two equivalent O(8)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the eighth O site, O(8) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(10)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(10)Ca4V2 octahedra, faces with two equivalent O(7)Ca4V2 octahedra, and faces with two equivalent O(9)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the ninth O site, O(9) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(7)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(7)Ca4V2 octahedra, faces with two equivalent O(10)Ca4V2 octahedra, and faces with two equivalent O(8)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the tenth O site, O(10) is bonded to one Ca(1), one Ca(2), one Ca(3), one Ca(4), one V(1), and one V(2) atom to form distorted OCa4V2 octahedra that share corners with two equivalent O(8)Ca4V2 octahedra, corners with two equivalent O(1)Ca2Al2 tetrahedra, corners with two equivalent O(2)Ca2Al2 tetrahedra, edges with two equivalent O(8)Ca4V2 octahedra, faces with two equivalent O(7)Ca4V2 octahedra, and faces with two equivalent O(9)Ca4V2 octahedra. The corner-sharing octahedral tilt angles are 1°.