The compound described by NaMnSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Mn(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(1)O6 octahedra. 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 three equivalent Mn(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-60°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Mn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent Mn(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_NaMn(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.434
_cell_length_b   6.519
_cell_length_c   6.519
_cell_angle_alpha   84.363
_cell_angle_beta   78.692
_cell_angle_gamma   78.692
_symmetry_Int_Tables_number   1
_cell_volume   221.601
_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
  Na  Na0  1  0.250  0.704  0.296  1.0
  Na  Na1  1  0.750  0.296  0.704  1.0
  Mn  Mn2  1  0.250  0.096  0.904  1.0
  Mn  Mn3  1  0.750  0.904  0.096  1.0
  Si  Si4  1  0.253  0.206  0.381  1.0
  Si  Si5  1  0.753  0.381  0.206  1.0
  Si  Si6  1  0.247  0.619  0.794  1.0
  Si  Si7  1  0.747  0.794  0.619  1.0
  O  O8  1  0.479  0.349  0.362  1.0
  O  O9  1  0.021  0.638  0.651  1.0
  O  O10  1  0.521  0.651  0.638  1.0
  O  O11  1  0.979  0.362  0.349  1.0
  O  O12  1  0.196  0.103  0.618  1.0
  O  O13  1  0.304  0.382  0.897  1.0
  O  O14  1  0.804  0.897  0.382  1.0
  O  O15  1  0.696  0.618  0.103  1.0
  O  O16  1  0.839  0.194  0.042  1.0
  O  O17  1  0.661  0.958  0.806  1.0
  O  O18  1  0.161  0.806  0.958  1.0
  O  O19  1  0.339  0.042  0.194  1.0
[/CIF]
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The compound described by NaMnSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Mn(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(1)O6 octahedra. 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 three equivalent Mn(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-60°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Mn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent Mn(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_NaMn(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.434
_cell_length_b   6.519
_cell_length_c   6.519
_cell_angle_alpha   84.363
_cell_angle_beta   78.692
_cell_angle_gamma   78.692
_symmetry_Int_Tables_number   1
_cell_volume   221.601
_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
  Na  Na0  1  0.250  0.704  0.296  1.0
  Na  Na1  1  0.750  0.296  0.704  1.0
  Mn  Mn2  1  0.250  0.096  0.904  1.0
  Mn  Mn3  1  0.750  0.904  0.096  1.0
  Si  Si4  1  0.253  0.206  0.381  1.0
  Si  Si5  1  0.753  0.381  0.206  1.0
  Si  Si6  1  0.247  0.619  0.794  1.0
  Si  Si7  1  0.747  0.794  0.619  1.0
  O  O8  1  0.479  0.349  0.362  1.0
  O  O9  1  0.021  0.638  0.651  1.0
  O  O10  1  0.521  0.651  0.638  1.0
  O  O11  1  0.979  0.362  0.349  1.0
  O  O12  1  0.196  0.103  0.618  1.0
  O  O13  1  0.304  0.382  0.897  1.0
  O  O14  1  0.804  0.897  0.382  1.0
  O  O15  1  0.696  0.618  0.103  1.0
  O  O16  1  0.839  0.194  0.042  1.0
  O  O17  1  0.661  0.958  0.806  1.0
  O  O18  1  0.161  0.806  0.958  1.0
  O  O19  1  0.339  0.042  0.194  1.0
[/CIF]
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