The compound described by Ca8Mn6Al2O23 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted q6 geometry to one O(4), two equivalent O(2), four equivalent O(6), and four equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded to one O(1), one O(5), two equivalent O(3), four equivalent O(6), and four equivalent O(7) atoms to form CaO12 cuboctahedra that share corners with four equivalent Ca(2)O12 cuboctahedra, faces with four equivalent Ca(2)O12 cuboctahedra, faces with two equivalent Mn(2)O6 octahedra, faces with four equivalent Mn(1)O6 octahedra, and faces with two equivalent Al(1)O5 square pyramids. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(3), two equivalent O(6), and two equivalent O(7) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Al(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mn site, Mn(2) is bonded to one O(4), one O(5), and four equivalent O(7) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. Al(1) is bonded to one O(1) and four equivalent O(6) atoms to form distorted AlO5 square pyramids that share corners with four equivalent Mn(1)O6 octahedra,  a cornercorner with one Al(1)O5 square pyramid, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 15°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to four equivalent Ca(2) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ca(1) and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded to four equivalent Ca(2) and two equivalent Mn(1) atoms to form a mixture of distorted corner and edge-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the fourth O site, O(4) is bonded to four equivalent Ca(1) and two equivalent Mn(2) atoms to form distorted corner-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to four equivalent Ca(2) and two equivalent Mn(2) atoms to form a mixture of distorted corner and edge-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Al(1) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Mn(2) atom. is represented by the CIF card [CIF]
data_Ca8Mn6Al2O23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.530
_cell_length_b   7.530
_cell_length_c   7.727
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   438.144
_cell_formula_units_Z   1
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  0.259  0.259  0.250  1.0
  Ca  Ca1  1  0.255  0.255  0.750  1.0
  Ca  Ca2  1  0.259  0.741  0.250  1.0
  Ca  Ca3  1  0.255  0.745  0.750  1.0
  Ca  Ca4  1  0.741  0.259  0.250  1.0
  Ca  Ca5  1  0.745  0.255  0.750  1.0
  Ca  Ca6  1  0.741  0.741  0.250  1.0
  Ca  Ca7  1  0.745  0.745  0.750  1.0
  Mn  Mn8  1  0.000  0.500  0.005  1.0
  Mn  Mn9  1  0.000  0.500  0.495  1.0
  Mn  Mn10  1  0.500  0.000  0.005  1.0
  Mn  Mn11  1  0.500  0.000  0.495  1.0
  Mn  Mn12  1  0.500  0.500  0.999  1.0
  Mn  Mn13  1  0.500  0.500  0.501  1.0
  Al  Al14  1  0.000  0.000  0.976  1.0
  Al  Al15  1  0.000  0.000  0.524  1.0
  O  O16  1  0.000  0.000  0.750  1.0
  O  O17  1  0.000  0.500  0.250  1.0
  O  O18  1  0.000  0.500  0.750  1.0
  O  O19  1  0.500  0.000  0.250  1.0
  O  O20  1  0.500  0.000  0.750  1.0
  O  O21  1  0.500  0.500  0.250  1.0
  O  O22  1  0.500  0.500  0.750  1.0
  O  O23  1  0.242  0.000  0.021  1.0
  O  O24  1  0.242  0.000  0.479  1.0
  O  O25  1  0.250  0.500  0.999  1.0
  O  O26  1  0.250  0.500  0.501  1.0
  O  O27  1  0.758  0.000  0.021  1.0
  O  O28  1  0.758  0.000  0.479  1.0
  O  O29  1  0.750  0.500  0.999  1.0
  O  O30  1  0.750  0.500  0.501  1.0
  O  O31  1  0.000  0.242  0.021  1.0
  O  O32  1  0.000  0.242  0.479  1.0
  O  O33  1  0.000  0.758  0.021  1.0
  O  O34  1  0.000  0.758  0.479  1.0
  O  O35  1  0.500  0.250  0.999  1.0
  O  O36  1  0.500  0.250  0.501  1.0
  O  O37  1  0.500  0.750  0.999  1.0
  O  O38  1  0.500  0.750  0.501  1.0
[/CIF]
.
The compound described by Ca8Mn6Al2O23 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted q6 geometry to one O(4), two equivalent O(2), four equivalent O(6), and four equivalent O(7) atoms. In the second Ca site, Ca(2) is bonded to one O(1), one O(5), two equivalent O(3), four equivalent O(6), and four equivalent O(7) atoms to form CaO12 cuboctahedra that share corners with four equivalent Ca(2)O12 cuboctahedra, faces with four equivalent Ca(2)O12 cuboctahedra, faces with two equivalent Mn(2)O6 octahedra, faces with four equivalent Mn(1)O6 octahedra, and faces with two equivalent Al(1)O5 square pyramids. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), one O(3), two equivalent O(6), and two equivalent O(7) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Al(1)O5 square pyramids, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mn site, Mn(2) is bonded to one O(4), one O(5), and four equivalent O(7) atoms to form MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. Al(1) is bonded to one O(1) and four equivalent O(6) atoms to form distorted AlO5 square pyramids that share corners with four equivalent Mn(1)O6 octahedra,  a cornercorner with one Al(1)O5 square pyramid, and faces with four equivalent Ca(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 15°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to four equivalent Ca(2) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ca(1) and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded to four equivalent Ca(2) and two equivalent Mn(1) atoms to form a mixture of distorted corner and edge-sharing OCa4Mn2 octahedra. The corner-sharing octahedral tilt angles are 2°. In the fourth O site, O(4) is bonded to four equivalent Ca(1) and two equivalent Mn(2) atoms to form distorted corner-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to four equivalent Ca(2) and two equivalent Mn(2) atoms to form a mixture of distorted corner and edge-sharing OCa4Mn2 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Al(1) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to two equivalent Ca(1), two equivalent Ca(2), one Mn(1), and one Mn(2) atom. is represented by the CIF card [CIF]
data_Ca8Mn6Al2O23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.530
_cell_length_b   7.530
_cell_length_c   7.727
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   438.144
_cell_formula_units_Z   1
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  0.259  0.259  0.250  1.0
  Ca  Ca1  1  0.255  0.255  0.750  1.0
  Ca  Ca2  1  0.259  0.741  0.250  1.0
  Ca  Ca3  1  0.255  0.745  0.750  1.0
  Ca  Ca4  1  0.741  0.259  0.250  1.0
  Ca  Ca5  1  0.745  0.255  0.750  1.0
  Ca  Ca6  1  0.741  0.741  0.250  1.0
  Ca  Ca7  1  0.745  0.745  0.750  1.0
  Mn  Mn8  1  0.000  0.500  0.005  1.0
  Mn  Mn9  1  0.000  0.500  0.495  1.0
  Mn  Mn10  1  0.500  0.000  0.005  1.0
  Mn  Mn11  1  0.500  0.000  0.495  1.0
  Mn  Mn12  1  0.500  0.500  0.999  1.0
  Mn  Mn13  1  0.500  0.500  0.501  1.0
  Al  Al14  1  0.000  0.000  0.976  1.0
  Al  Al15  1  0.000  0.000  0.524  1.0
  O  O16  1  0.000  0.000  0.750  1.0
  O  O17  1  0.000  0.500  0.250  1.0
  O  O18  1  0.000  0.500  0.750  1.0
  O  O19  1  0.500  0.000  0.250  1.0
  O  O20  1  0.500  0.000  0.750  1.0
  O  O21  1  0.500  0.500  0.250  1.0
  O  O22  1  0.500  0.500  0.750  1.0
  O  O23  1  0.242  0.000  0.021  1.0
  O  O24  1  0.242  0.000  0.479  1.0
  O  O25  1  0.250  0.500  0.999  1.0
  O  O26  1  0.250  0.500  0.501  1.0
  O  O27  1  0.758  0.000  0.021  1.0
  O  O28  1  0.758  0.000  0.479  1.0
  O  O29  1  0.750  0.500  0.999  1.0
  O  O30  1  0.750  0.500  0.501  1.0
  O  O31  1  0.000  0.242  0.021  1.0
  O  O32  1  0.000  0.242  0.479  1.0
  O  O33  1  0.000  0.758  0.021  1.0
  O  O34  1  0.000  0.758  0.479  1.0
  O  O35  1  0.500  0.250  0.999  1.0
  O  O36  1  0.500  0.250  0.501  1.0
  O  O37  1  0.500  0.750  0.999  1.0
  O  O38  1  0.500  0.750  0.501  1.0
[/CIF]
.