The compound described by Ca2MnAl2Si3O13 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(2), one O(9), two equivalent O(1), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), two equivalent O(5), and four equivalent O(4) atoms. Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(9) atoms to form MnO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(10), two equivalent O(5), 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(2)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded in a distorted see-saw-like geometry to one O(3), one O(6), and two equivalent O(4) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(7), one O(9), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. In the second Si site, Si(2) is bonded to one O(6), one O(8), and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. In the third Si site, Si(3) is bonded to one O(2), one O(8), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are ten inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(2) atom. In the second O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Al(1) and one Si(1) atom. In the third O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the fourth O site, O(9) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Mn(1), and one Si(1) atom. In the fifth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Al(1) atoms. In the sixth O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Mn(1), and one Si(3) atom. In the seventh O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one Si(3) atom. In the eighth O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Mn(1) and one Al(2) atom. In the ninth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ca(2), one Al(2), and one Si(1) atom. In the tenth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Al(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_Ca2MnAl2Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.758
_cell_length_b   8.917
_cell_length_c   10.359
_cell_angle_alpha   66.278
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   486.928
_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  0.750  0.607  0.157  1.0
  Ca  Ca1  1  0.250  0.393  0.843  1.0
  Ca  Ca2  1  0.750  0.206  0.418  1.0
  Ca  Ca3  1  0.250  0.794  0.582  1.0
  Mn  Mn4  1  0.500  0.000  0.000  1.0
  Mn  Mn5  1  0.000  0.000  0.000  1.0
  Al  Al6  1  0.500  0.500  0.500  1.0
  Al  Al7  1  0.000  0.500  0.500  1.0
  Al  Al8  1  0.250  0.049  0.251  1.0
  Al  Al9  1  0.750  0.951  0.749  1.0
  Si  Si10  1  0.750  0.869  0.322  1.0
  Si  Si11  1  0.250  0.131  0.678  1.0
  Si  Si12  1  0.250  0.412  0.267  1.0
  Si  Si13  1  0.750  0.588  0.733  1.0
  Si  Si14  1  0.750  0.299  0.043  1.0
  Si  Si15  1  0.250  0.701  0.957  1.0
  O  O16  1  0.510  0.200  0.033  1.0
  O  O17  1  0.010  0.800  0.967  1.0
  O  O18  1  0.490  0.800  0.967  1.0
  O  O19  1  0.990  0.200  0.033  1.0
  O  O20  1  0.750  0.338  0.180  1.0
  O  O21  1  0.250  0.662  0.820  1.0
  O  O22  1  0.250  0.938  0.133  1.0
  O  O23  1  0.750  0.062  0.867  1.0
  O  O24  1  0.515  0.956  0.353  1.0
  O  O25  1  0.015  0.044  0.647  1.0
  O  O26  1  0.485  0.044  0.647  1.0
  O  O27  1  0.985  0.956  0.353  1.0
  O  O28  1  0.482  0.460  0.333  1.0
  O  O29  1  0.982  0.540  0.667  1.0
  O  O30  1  0.518  0.540  0.667  1.0
  O  O31  1  0.018  0.460  0.333  1.0
  O  O32  1  0.250  0.220  0.295  1.0
  O  O33  1  0.750  0.780  0.705  1.0
  O  O34  1  0.750  0.670  0.408  1.0
  O  O35  1  0.250  0.330  0.592  1.0
  O  O36  1  0.250  0.523  0.094  1.0
  O  O37  1  0.750  0.477  0.906  1.0
  O  O38  1  0.750  0.896  0.150  1.0
  O  O39  1  0.250  0.104  0.850  1.0
  O  O40  1  0.250  0.640  0.450  1.0
  O  O41  1  0.750  0.360  0.550  1.0
[/CIF]
.
The compound described by Ca2MnAl2Si3O13 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(2), one O(9), two equivalent O(1), and two equivalent O(5) atoms. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(10), one O(2), two equivalent O(5), and four equivalent O(4) atoms. Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(9) atoms to form MnO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Mn(1)O6 octahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(10), two equivalent O(5), 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(2)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded in a distorted see-saw-like geometry to one O(3), one O(6), and two equivalent O(4) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(7), one O(9), and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. In the second Si site, Si(2) is bonded to one O(6), one O(8), and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O6 octahedra and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. In the third Si site, Si(3) is bonded to one O(2), one O(8), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Mn(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are ten inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(2) atom. In the second O site, O(7) is bonded in a 3-coordinate geometry to two equivalent Al(1) and one Si(1) atom. In the third O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the fourth O site, O(9) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Mn(1), and one Si(1) atom. In the fifth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Ca(2) and two equivalent Al(1) atoms. In the sixth O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Mn(1), and one Si(3) atom. In the seventh O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one Si(3) atom. In the eighth O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Mn(1) and one Al(2) atom. In the ninth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ca(2), one Al(2), and one Si(1) atom. In the tenth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Al(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_Ca2MnAl2Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.758
_cell_length_b   8.917
_cell_length_c   10.359
_cell_angle_alpha   66.278
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   486.928
_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  0.750  0.607  0.157  1.0
  Ca  Ca1  1  0.250  0.393  0.843  1.0
  Ca  Ca2  1  0.750  0.206  0.418  1.0
  Ca  Ca3  1  0.250  0.794  0.582  1.0
  Mn  Mn4  1  0.500  0.000  0.000  1.0
  Mn  Mn5  1  0.000  0.000  0.000  1.0
  Al  Al6  1  0.500  0.500  0.500  1.0
  Al  Al7  1  0.000  0.500  0.500  1.0
  Al  Al8  1  0.250  0.049  0.251  1.0
  Al  Al9  1  0.750  0.951  0.749  1.0
  Si  Si10  1  0.750  0.869  0.322  1.0
  Si  Si11  1  0.250  0.131  0.678  1.0
  Si  Si12  1  0.250  0.412  0.267  1.0
  Si  Si13  1  0.750  0.588  0.733  1.0
  Si  Si14  1  0.750  0.299  0.043  1.0
  Si  Si15  1  0.250  0.701  0.957  1.0
  O  O16  1  0.510  0.200  0.033  1.0
  O  O17  1  0.010  0.800  0.967  1.0
  O  O18  1  0.490  0.800  0.967  1.0
  O  O19  1  0.990  0.200  0.033  1.0
  O  O20  1  0.750  0.338  0.180  1.0
  O  O21  1  0.250  0.662  0.820  1.0
  O  O22  1  0.250  0.938  0.133  1.0
  O  O23  1  0.750  0.062  0.867  1.0
  O  O24  1  0.515  0.956  0.353  1.0
  O  O25  1  0.015  0.044  0.647  1.0
  O  O26  1  0.485  0.044  0.647  1.0
  O  O27  1  0.985  0.956  0.353  1.0
  O  O28  1  0.482  0.460  0.333  1.0
  O  O29  1  0.982  0.540  0.667  1.0
  O  O30  1  0.518  0.540  0.667  1.0
  O  O31  1  0.018  0.460  0.333  1.0
  O  O32  1  0.250  0.220  0.295  1.0
  O  O33  1  0.750  0.780  0.705  1.0
  O  O34  1  0.750  0.670  0.408  1.0
  O  O35  1  0.250  0.330  0.592  1.0
  O  O36  1  0.250  0.523  0.094  1.0
  O  O37  1  0.750  0.477  0.906  1.0
  O  O38  1  0.750  0.896  0.150  1.0
  O  O39  1  0.250  0.104  0.850  1.0
  O  O40  1  0.250  0.640  0.450  1.0
  O  O41  1  0.750  0.360  0.550  1.0
[/CIF]
.