The material described by MgMn2(SiO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(4) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) 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(2)O6 octahedra. In the second Mn site, Mn(2) 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(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(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. 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(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-61°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(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(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1), one Mn(2), 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 in a 3-coordinate geometry to one Mn(1), one Mn(2), and one Si(1) atom. is represented by the CIF card [CIF]
data_MgMn2(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.275
_cell_length_b   6.921
_cell_length_c   6.920
_cell_angle_alpha   78.756
_cell_angle_beta   73.911
_cell_angle_gamma   73.910
_symmetry_Int_Tables_number   1
_cell_volume   231.302
_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
  Mg  Mg0  1  0.750  0.586  0.414  1.0
  Mn  Mn1  1  0.250  0.123  0.877  1.0
  Mn  Mn2  1  0.750  0.915  0.085  1.0
  Si  Si3  1  0.262  0.177  0.369  1.0
  Si  Si4  1  0.238  0.631  0.823  1.0
  Si  Si5  1  0.755  0.365  0.167  1.0
  Si  Si6  1  0.745  0.833  0.635  1.0
  O  O7  1  0.463  0.335  0.317  1.0
  O  O8  1  0.037  0.683  0.665  1.0
  O  O9  1  0.546  0.662  0.687  1.0
  O  O10  1  0.954  0.313  0.338  1.0
  O  O11  1  0.221  0.087  0.604  1.0
  O  O12  1  0.279  0.396  0.913  1.0
  O  O13  1  0.789  0.872  0.389  1.0
  O  O14  1  0.711  0.611  0.128  1.0
  O  O15  1  0.867  0.201  0.005  1.0
  O  O16  1  0.633  0.995  0.799  1.0
  O  O17  1  0.370  0.028  0.189  1.0
  O  O18  1  0.130  0.811  0.972  1.0
[/CIF]
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The material described by MgMn2(SiO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(4) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) 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(2)O6 octahedra. In the second Mn site, Mn(2) 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(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(2)O6 octahedra, corners with two equivalent Mn(1)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 35-58°. 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(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-61°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(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(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1), one Mn(2), 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 in a 3-coordinate geometry to one Mn(1), one Mn(2), and one Si(1) atom. is represented by the CIF card [CIF]
data_MgMn2(SiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.275
_cell_length_b   6.921
_cell_length_c   6.920
_cell_angle_alpha   78.756
_cell_angle_beta   73.911
_cell_angle_gamma   73.910
_symmetry_Int_Tables_number   1
_cell_volume   231.302
_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
  Mg  Mg0  1  0.750  0.586  0.414  1.0
  Mn  Mn1  1  0.250  0.123  0.877  1.0
  Mn  Mn2  1  0.750  0.915  0.085  1.0
  Si  Si3  1  0.262  0.177  0.369  1.0
  Si  Si4  1  0.238  0.631  0.823  1.0
  Si  Si5  1  0.755  0.365  0.167  1.0
  Si  Si6  1  0.745  0.833  0.635  1.0
  O  O7  1  0.463  0.335  0.317  1.0
  O  O8  1  0.037  0.683  0.665  1.0
  O  O9  1  0.546  0.662  0.687  1.0
  O  O10  1  0.954  0.313  0.338  1.0
  O  O11  1  0.221  0.087  0.604  1.0
  O  O12  1  0.279  0.396  0.913  1.0
  O  O13  1  0.789  0.872  0.389  1.0
  O  O14  1  0.711  0.611  0.128  1.0
  O  O15  1  0.867  0.201  0.005  1.0
  O  O16  1  0.633  0.995  0.799  1.0
  O  O17  1  0.370  0.028  0.189  1.0
  O  O18  1  0.130  0.811  0.972  1.0
[/CIF]
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