The structure described by CaMn2(SiO3)4 crystallizes in the monoclinic C2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Si(2)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form distorted MnO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, 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(1), one O(2), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-61°. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-59°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Mn(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Mn(1), one Mn(2), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OCaMn2Si tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaMn2(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.301
_cell_length_b   6.695
_cell_length_c   6.695
_cell_angle_alpha   84.512
_cell_angle_beta   76.160
_cell_angle_gamma   76.161
_symmetry_Int_Tables_number   1
_cell_volume   223.786
_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  0.250  0.694  0.306  1.0
  Mn  Mn1  1  0.750  0.909  0.091  1.0
  Mn  Mn2  1  0.250  0.111  0.889  1.0
  Si  Si3  1  0.271  0.198  0.383  1.0
  Si  Si4  1  0.229  0.617  0.802  1.0
  Si  Si5  1  0.780  0.380  0.198  1.0
  Si  Si6  1  0.720  0.802  0.620  1.0
  O  O7  1  0.495  0.340  0.352  1.0
  O  O8  1  0.005  0.648  0.660  1.0
  O  O9  1  0.493  0.667  0.633  1.0
  O  O10  1  0.007  0.367  0.333  1.0
  O  O11  1  0.208  0.090  0.606  1.0
  O  O12  1  0.292  0.394  0.910  1.0
  O  O13  1  0.813  0.885  0.385  1.0
  O  O14  1  0.687  0.615  0.115  1.0
  O  O15  1  0.880  0.192  0.035  1.0
  O  O16  1  0.620  0.965  0.808  1.0
  O  O17  1  0.373  0.025  0.199  1.0
  O  O18  1  0.127  0.801  0.975  1.0
[/CIF]
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The structure described by CaMn2(SiO3)4 crystallizes in the monoclinic C2 space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with four equivalent Si(2)O4 tetrahedra, and edges with two equivalent Mn(2)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form distorted MnO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, 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(1), one O(2), one O(3), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-61°. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 34-59°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mn(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ca(1), one Mn(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(2) atom. In the sixth O site, O(6) is bonded to one Ca(1), one Mn(1), one Mn(2), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OCaMn2Si tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaMn2(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.301
_cell_length_b   6.695
_cell_length_c   6.695
_cell_angle_alpha   84.512
_cell_angle_beta   76.160
_cell_angle_gamma   76.161
_symmetry_Int_Tables_number   1
_cell_volume   223.786
_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  0.250  0.694  0.306  1.0
  Mn  Mn1  1  0.750  0.909  0.091  1.0
  Mn  Mn2  1  0.250  0.111  0.889  1.0
  Si  Si3  1  0.271  0.198  0.383  1.0
  Si  Si4  1  0.229  0.617  0.802  1.0
  Si  Si5  1  0.780  0.380  0.198  1.0
  Si  Si6  1  0.720  0.802  0.620  1.0
  O  O7  1  0.495  0.340  0.352  1.0
  O  O8  1  0.005  0.648  0.660  1.0
  O  O9  1  0.493  0.667  0.633  1.0
  O  O10  1  0.007  0.367  0.333  1.0
  O  O11  1  0.208  0.090  0.606  1.0
  O  O12  1  0.292  0.394  0.910  1.0
  O  O13  1  0.813  0.885  0.385  1.0
  O  O14  1  0.687  0.615  0.115  1.0
  O  O15  1  0.880  0.192  0.035  1.0
  O  O16  1  0.620  0.965  0.808  1.0
  O  O17  1  0.373  0.025  0.199  1.0
  O  O18  1  0.127  0.801  0.975  1.0
[/CIF]
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