The material described by Ca2Mn2Si4O17 crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 6-coordinate geometry to one O(3), one O(7), two equivalent O(1), and two equivalent O(4) atoms. Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Mn(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-59°. In the second Si site, Si(2) is bonded to one O(3), one O(5), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Mn(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Si(2) atoms. In the sixth O site, O(6) is bonded in a water-like geometry to two equivalent Mn(1) atoms. In the seventh O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. is represented by the CIF card [CIF]
data_Ca2Mn2Si4O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.342
_cell_length_b   5.342
_cell_length_c   11.929
_cell_angle_alpha   83.115
_cell_angle_beta   83.115
_cell_angle_gamma   67.835
_symmetry_Int_Tables_number   1
_cell_volume   311.904
_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  0.703  0.703  0.729  1.0
  Ca  Ca1  1  0.297  0.297  0.271  1.0
  Mn  Mn2  1  0.000  0.500  0.000  1.0
  Mn  Mn3  1  0.500  0.000  0.000  1.0
  Si  Si4  1  0.048  0.048  0.849  1.0
  Si  Si5  1  0.952  0.952  0.151  1.0
  Si  Si6  1  0.119  0.119  0.590  1.0
  Si  Si7  1  0.881  0.881  0.410  1.0
  O  O8  1  0.909  0.367  0.874  1.0
  O  O9  1  0.367  0.909  0.874  1.0
  O  O10  1  0.091  0.633  0.126  1.0
  O  O11  1  0.633  0.091  0.126  1.0
  O  O12  1  0.872  0.872  0.923  1.0
  O  O13  1  0.128  0.128  0.077  1.0
  O  O14  1  0.006  0.006  0.719  1.0
  O  O15  1  0.994  0.994  0.281  1.0
  O  O16  1  0.983  0.448  0.592  1.0
  O  O17  1  0.448  0.983  0.592  1.0
  O  O18  1  0.017  0.552  0.408  1.0
  O  O19  1  0.552  0.017  0.408  1.0
  O  O20  1  0.000  0.000  0.500  1.0
  O  O21  1  0.364  0.364  0.941  1.0
  O  O22  1  0.636  0.636  0.059  1.0
  O  O23  1  0.415  0.415  0.751  1.0
  O  O24  1  0.585  0.585  0.249  1.0
[/CIF]
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The material described by Ca2Mn2Si4O17 crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 6-coordinate geometry to one O(3), one O(7), two equivalent O(1), and two equivalent O(4) atoms. Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(1)O6 octahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Mn(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-59°. In the second Si site, Si(2) is bonded to one O(3), one O(5), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ca(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Mn(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Si(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Si(2) atoms. In the sixth O site, O(6) is bonded in a water-like geometry to two equivalent Mn(1) atoms. In the seventh O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. is represented by the CIF card [CIF]
data_Ca2Mn2Si4O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.342
_cell_length_b   5.342
_cell_length_c   11.929
_cell_angle_alpha   83.115
_cell_angle_beta   83.115
_cell_angle_gamma   67.835
_symmetry_Int_Tables_number   1
_cell_volume   311.904
_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  0.703  0.703  0.729  1.0
  Ca  Ca1  1  0.297  0.297  0.271  1.0
  Mn  Mn2  1  0.000  0.500  0.000  1.0
  Mn  Mn3  1  0.500  0.000  0.000  1.0
  Si  Si4  1  0.048  0.048  0.849  1.0
  Si  Si5  1  0.952  0.952  0.151  1.0
  Si  Si6  1  0.119  0.119  0.590  1.0
  Si  Si7  1  0.881  0.881  0.410  1.0
  O  O8  1  0.909  0.367  0.874  1.0
  O  O9  1  0.367  0.909  0.874  1.0
  O  O10  1  0.091  0.633  0.126  1.0
  O  O11  1  0.633  0.091  0.126  1.0
  O  O12  1  0.872  0.872  0.923  1.0
  O  O13  1  0.128  0.128  0.077  1.0
  O  O14  1  0.006  0.006  0.719  1.0
  O  O15  1  0.994  0.994  0.281  1.0
  O  O16  1  0.983  0.448  0.592  1.0
  O  O17  1  0.448  0.983  0.592  1.0
  O  O18  1  0.017  0.552  0.408  1.0
  O  O19  1  0.552  0.017  0.408  1.0
  O  O20  1  0.000  0.000  0.500  1.0
  O  O21  1  0.364  0.364  0.941  1.0
  O  O22  1  0.636  0.636  0.059  1.0
  O  O23  1  0.415  0.415  0.751  1.0
  O  O24  1  0.585  0.585  0.249  1.0
[/CIF]
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