Mn2Al3Si3O14 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 7-coordinate geometry to one O(11), one O(4), one O(8), two equivalent O(2), and two equivalent O(9) atoms. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(1), one O(6), two equivalent O(7), and two equivalent O(9) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(8), and two equivalent O(9) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(2)O6 octahedra. In the third Al site, Al(3) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(7) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Al(3)O6 octahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with two equivalent Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. In the second Si site, Si(2) is bonded to one O(11), one O(6), and two equivalent O(9) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(2)O6 octahedra and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. In the third Si site, Si(3) is bonded to one O(11), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(3)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-63°. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mn(2), two equivalent Al(2), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mn(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Al(3) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Mn(1), two equivalent Al(1), and one Si(3) atom. In the fifth O site, O(5) is bonded in a water-like geometry to two equivalent Al(1) atoms. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Mn(2) and one Si(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mn(2), one Al(3), and one Si(3) atom. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Mn(1) and two equivalent Al(2) atoms. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(2), one Al(2), and one Si(2) atom. In the tenth O site, O(10) is bonded in a water-like geometry to two equivalent Al(3) atoms. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Mn(1), one Si(2), and one Si(3) atom.
Mn2Al3Si3O14 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 7-coordinate geometry to one O(11), one O(4), one O(8), two equivalent O(2), and two equivalent O(9) atoms. The Mn(1)-O(11) bond length is 2.63 Å. The Mn(1)-O(4) bond length is 2.46 Å. The Mn(1)-O(8) bond length is 1.92 Å. Both Mn(1)-O(2) bond lengths are 2.07 Å. Both Mn(1)-O(9) bond lengths are 2.42 Å. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(1), one O(6), two equivalent O(7), and two equivalent O(9) atoms. The Mn(2)-O(1) bond length is 2.67 Å. The Mn(2)-O(6) bond length is 2.01 Å. Both Mn(2)-O(7) bond lengths are 2.09 Å. Both Mn(2)-O(9) bond lengths are 2.32 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. Both Al(1)-O(2) bond lengths are 1.91 Å. Both Al(1)-O(4) bond lengths are 2.01 Å. Both Al(1)-O(5) bond lengths are 1.84 Å. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(8), and two equivalent O(9) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(2)O6 octahedra. Both Al(2)-O(1) bond lengths are 1.98 Å. Both Al(2)-O(8) bond lengths are 1.85 Å. Both Al(2)-O(9) bond lengths are 2.00 Å. In the third Al site, Al(3) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(7) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Al(3)O6 octahedra. Both Al(3)-O(10) bond lengths are 1.86 Å. Both Al(3)-O(3) bond lengths are 1.94 Å. Both Al(3)-O(7) bond lengths are 1.90 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with two equivalent Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-60°. The Si(1)-O(1) bond length is 1.66 Å. The Si(1)-O(3) bond length is 1.63 Å. Both Si(1)-O(2) bond lengths are 1.64 Å. In the second Si site, Si(2) is bonded to one O(11), one O(6), and two equivalent O(9) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(2)O6 octahedra and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. The Si(2)-O(11) bond length is 1.68 Å. The Si(2)-O(6) bond length is 1.59 Å. Both Si(2)-O(9) bond lengths are 1.69 Å. In the third Si site, Si(3) is bonded to one O(11), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(3)O6 octahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-63°. The Si(3)-O(11) bond length is 1.65 Å. The Si(3)-O(4) bond length is 1.65 Å. Both Si(3)-O(7) bond lengths are 1.64 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mn(2), two equivalent Al(2), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mn(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Al(3) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Mn(1), two equivalent Al(1), and one Si(3) atom. In the fifth O site, O(5) is bonded in a water-like geometry to two equivalent Al(1) atoms. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Mn(2) and one Si(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mn(2), one Al(3), and one Si(3) atom. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Mn(1) and two equivalent Al(2) atoms. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(2), one Al(2), and one Si(2) atom. In the tenth O site, O(10) is bonded in a water-like geometry to two equivalent Al(3) atoms. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Mn(1), one Si(2), and one Si(3) atom.