The material described by Ca4Mn2Al2O11 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(7), one O(8), two equivalent O(3), two equivalent O(4), and three equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(5), one O(6), one O(7), one O(8), one O(9), and three equivalent O(1) atoms. Mn(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form MnO6 octahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 7-28°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with four equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-22°. In the second Al site, Al(2) is bonded to two equivalent O(1) and two equivalent O(9) atoms to form AlO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and  an edgeedge with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(2), one Mn(1), and one Al(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Mn(1), and one Al(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ca(1) and two equivalent Al(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Ca(1) and two equivalent Al(1) atoms to form distorted OCa4Al2 octahedra that share corners with two equivalent O(4)Ca4Al2 octahedra, corners with two equivalent O(8)Ca4Mn2 octahedra, corners with four equivalent O(7)Ca4Mn2 octahedra,  an edgeedge with one O(8)Ca4Mn2 octahedra, and edges with two equivalent O(4)Ca4Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-64°. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(2) and two equivalent Mn(1) atoms. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Ca(2) and two equivalent Mn(1) atoms. In the seventh O site, O(7) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Mn(1) atoms to form distorted OCa4Mn2 octahedra that share corners with four equivalent O(4)Ca4Al2 octahedra, corners with two equivalent O(9)Ca2Al2 trigonal pyramids, and faces with two equivalent O(8)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. In the eighth O site, O(8) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Mn(1) atoms to form distorted OCa4Mn2 octahedra that share corners with two equivalent O(4)Ca4Al2 octahedra, corners with two equivalent O(9)Ca2Al2 trigonal pyramids,  an edgeedge with one O(4)Ca4Al2 octahedra, and faces with two equivalent O(7)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the ninth O site, O(9) is bonded to two equivalent Ca(2) and two equivalent Al(2) atoms to form OCa2Al2 trigonal pyramids that share corners with two equivalent O(7)Ca4Mn2 octahedra, corners with two equivalent O(8)Ca4Mn2 octahedra, and  an edgeedge with one O(9)Ca2Al2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 23-49°. is represented by the CIF file [CIF]
data_Ca4Mn2Al2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.290
_cell_length_b   15.290
_cell_length_c   5.356
_cell_angle_alpha   80.008
_cell_angle_beta   80.008
_cell_angle_gamma   151.199
_symmetry_Int_Tables_number   1
_cell_volume   432.150
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.949  0.564  0.492  1.0
  Ca  Ca1  1  0.051  0.436  0.508  1.0
  Ca  Ca2  1  0.436  0.051  0.508  1.0
  Ca  Ca3  1  0.564  0.949  0.492  1.0
  Ca  Ca4  1  0.713  0.855  0.447  1.0
  Ca  Ca5  1  0.287  0.145  0.553  1.0
  Ca  Ca6  1  0.145  0.287  0.553  1.0
  Ca  Ca7  1  0.855  0.713  0.447  1.0
  Mn  Mn8  1  0.385  0.136  0.992  1.0
  Mn  Mn9  1  0.615  0.864  0.008  1.0
  Mn  Mn10  1  0.864  0.615  0.008  1.0
  Mn  Mn11  1  0.136  0.385  0.992  1.0
  Al  Al12  1  0.500  0.000  0.000  1.0
  Al  Al13  1  0.000  0.500  0.000  1.0
  Al  Al14  1  0.320  0.320  0.013  1.0
  Al  Al15  1  0.680  0.680  0.987  1.0
  O  O16  1  0.144  0.249  0.040  1.0
  O  O17  1  0.856  0.751  0.960  1.0
  O  O18  1  0.751  0.856  0.960  1.0
  O  O19  1  0.249  0.144  0.040  1.0
  O  O20  1  0.506  0.136  0.933  1.0
  O  O21  1  0.494  0.864  0.067  1.0
  O  O22  1  0.864  0.494  0.067  1.0
  O  O23  1  0.136  0.506  0.933  1.0
  O  O24  1  0.757  0.243  0.000  1.0
  O  O25  1  0.243  0.757  0.500  1.0
  O  O26  1  0.757  0.243  0.500  1.0
  O  O27  1  0.243  0.757  0.000  1.0
  O  O28  1  0.609  0.391  0.000  1.0
  O  O29  1  0.388  0.612  0.500  1.0
  O  O30  1  0.612  0.388  0.500  1.0
  O  O31  1  0.391  0.609  0.000  1.0
  O  O32  1  0.130  0.870  0.000  1.0
  O  O33  1  0.871  0.129  0.500  1.0
  O  O34  1  0.129  0.871  0.500  1.0
  O  O35  1  0.870  0.130  0.000  1.0
  O  O36  1  0.652  0.652  0.670  1.0
  O  O37  1  0.348  0.348  0.330  1.0
[/CIF]
.
The material described by Ca4Mn2Al2O11 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 9-coordinate geometry to one O(7), one O(8), two equivalent O(3), two equivalent O(4), and three equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(5), one O(6), one O(7), one O(8), one O(9), and three equivalent O(1) atoms. Mn(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom to form MnO6 octahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 7-28°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with four equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-22°. In the second Al site, Al(2) is bonded to two equivalent O(1) and two equivalent O(9) atoms to form AlO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and  an edgeedge with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(2), one Mn(1), and one Al(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Mn(1), and one Al(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Ca(1) and two equivalent Al(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Ca(1) and two equivalent Al(1) atoms to form distorted OCa4Al2 octahedra that share corners with two equivalent O(4)Ca4Al2 octahedra, corners with two equivalent O(8)Ca4Mn2 octahedra, corners with four equivalent O(7)Ca4Mn2 octahedra,  an edgeedge with one O(8)Ca4Mn2 octahedra, and edges with two equivalent O(4)Ca4Al2 octahedra. The corner-sharing octahedral tilt angles range from 0-64°. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(2) and two equivalent Mn(1) atoms. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Ca(2) and two equivalent Mn(1) atoms. In the seventh O site, O(7) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Mn(1) atoms to form distorted OCa4Mn2 octahedra that share corners with four equivalent O(4)Ca4Al2 octahedra, corners with two equivalent O(9)Ca2Al2 trigonal pyramids, and faces with two equivalent O(8)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 60-64°. In the eighth O site, O(8) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent Mn(1) atoms to form distorted OCa4Mn2 octahedra that share corners with two equivalent O(4)Ca4Al2 octahedra, corners with two equivalent O(9)Ca2Al2 trigonal pyramids,  an edgeedge with one O(4)Ca4Al2 octahedra, and faces with two equivalent O(7)Ca4Mn2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the ninth O site, O(9) is bonded to two equivalent Ca(2) and two equivalent Al(2) atoms to form OCa2Al2 trigonal pyramids that share corners with two equivalent O(7)Ca4Mn2 octahedra, corners with two equivalent O(8)Ca4Mn2 octahedra, and  an edgeedge with one O(9)Ca2Al2 trigonal pyramid. The corner-sharing octahedral tilt angles range from 23-49°. is represented by the CIF file [CIF]
data_Ca4Mn2Al2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.290
_cell_length_b   15.290
_cell_length_c   5.356
_cell_angle_alpha   80.008
_cell_angle_beta   80.008
_cell_angle_gamma   151.199
_symmetry_Int_Tables_number   1
_cell_volume   432.150
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.949  0.564  0.492  1.0
  Ca  Ca1  1  0.051  0.436  0.508  1.0
  Ca  Ca2  1  0.436  0.051  0.508  1.0
  Ca  Ca3  1  0.564  0.949  0.492  1.0
  Ca  Ca4  1  0.713  0.855  0.447  1.0
  Ca  Ca5  1  0.287  0.145  0.553  1.0
  Ca  Ca6  1  0.145  0.287  0.553  1.0
  Ca  Ca7  1  0.855  0.713  0.447  1.0
  Mn  Mn8  1  0.385  0.136  0.992  1.0
  Mn  Mn9  1  0.615  0.864  0.008  1.0
  Mn  Mn10  1  0.864  0.615  0.008  1.0
  Mn  Mn11  1  0.136  0.385  0.992  1.0
  Al  Al12  1  0.500  0.000  0.000  1.0
  Al  Al13  1  0.000  0.500  0.000  1.0
  Al  Al14  1  0.320  0.320  0.013  1.0
  Al  Al15  1  0.680  0.680  0.987  1.0
  O  O16  1  0.144  0.249  0.040  1.0
  O  O17  1  0.856  0.751  0.960  1.0
  O  O18  1  0.751  0.856  0.960  1.0
  O  O19  1  0.249  0.144  0.040  1.0
  O  O20  1  0.506  0.136  0.933  1.0
  O  O21  1  0.494  0.864  0.067  1.0
  O  O22  1  0.864  0.494  0.067  1.0
  O  O23  1  0.136  0.506  0.933  1.0
  O  O24  1  0.757  0.243  0.000  1.0
  O  O25  1  0.243  0.757  0.500  1.0
  O  O26  1  0.757  0.243  0.500  1.0
  O  O27  1  0.243  0.757  0.000  1.0
  O  O28  1  0.609  0.391  0.000  1.0
  O  O29  1  0.388  0.612  0.500  1.0
  O  O30  1  0.612  0.388  0.500  1.0
  O  O31  1  0.391  0.609  0.000  1.0
  O  O32  1  0.130  0.870  0.000  1.0
  O  O33  1  0.871  0.129  0.500  1.0
  O  O34  1  0.129  0.871  0.500  1.0
  O  O35  1  0.870  0.130  0.000  1.0
  O  O36  1  0.652  0.652  0.670  1.0
  O  O37  1  0.348  0.348  0.330  1.0
[/CIF]
.