The crystal structure described by Mn2Si2O7 crystallizes in the orthorhombic Ama2 space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(2)O5 square pyramids. In the second Mn site, Mn(2) is bonded to one O(2), two equivalent O(1), and two equivalent O(4) atoms to form MnO5 square pyramids 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(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra, corners with three equivalent Mn(2)O5 square pyramids, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-54°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mn(2) and two equivalent Si(1) atoms. 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 distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mn2Si2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.967
_cell_length_b   4.967
_cell_length_c   12.514
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   64.780
_symmetry_Int_Tables_number   1
_cell_volume   279.351
_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
  Mn  Mn0  1  0.043  0.957  0.000  1.0
  Mn  Mn1  1  0.043  0.957  0.500  1.0
  Mn  Mn2  1  0.009  0.923  0.250  1.0
  Mn  Mn3  1  0.077  0.991  0.750  1.0
  Si  Si4  1  0.379  0.293  0.133  1.0
  Si  Si5  1  0.379  0.293  0.367  1.0
  Si  Si6  1  0.707  0.621  0.633  1.0
  Si  Si7  1  0.707  0.621  0.867  1.0
  O  O8  1  0.237  0.661  0.136  1.0
  O  O9  1  0.237  0.661  0.364  1.0
  O  O10  1  0.339  0.763  0.636  1.0
  O  O11  1  0.339  0.763  0.864  1.0
  O  O12  1  0.279  0.192  0.250  1.0
  O  O13  1  0.808  0.721  0.750  1.0
  O  O14  1  0.828  0.742  0.535  1.0
  O  O15  1  0.828  0.742  0.965  1.0
  O  O16  1  0.258  0.172  0.035  1.0
  O  O17  1  0.258  0.172  0.465  1.0
  O  O18  1  0.848  0.253  0.865  1.0
  O  O19  1  0.848  0.253  0.635  1.0
  O  O20  1  0.747  0.152  0.135  1.0
  O  O21  1  0.747  0.152  0.365  1.0
[/CIF]
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The crystal structure described by Mn2Si2O7 crystallizes in the orthorhombic Ama2 space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Mn(2)O5 square pyramids. In the second Mn site, Mn(2) is bonded to one O(2), two equivalent O(1), and two equivalent O(4) atoms to form MnO5 square pyramids 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(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with three equivalent Mn(1)O6 octahedra, corners with three equivalent Mn(2)O5 square pyramids, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-54°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mn(2) and two equivalent Si(1) atoms. 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 distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mn2Si2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.967
_cell_length_b   4.967
_cell_length_c   12.514
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   64.780
_symmetry_Int_Tables_number   1
_cell_volume   279.351
_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
  Mn  Mn0  1  0.043  0.957  0.000  1.0
  Mn  Mn1  1  0.043  0.957  0.500  1.0
  Mn  Mn2  1  0.009  0.923  0.250  1.0
  Mn  Mn3  1  0.077  0.991  0.750  1.0
  Si  Si4  1  0.379  0.293  0.133  1.0
  Si  Si5  1  0.379  0.293  0.367  1.0
  Si  Si6  1  0.707  0.621  0.633  1.0
  Si  Si7  1  0.707  0.621  0.867  1.0
  O  O8  1  0.237  0.661  0.136  1.0
  O  O9  1  0.237  0.661  0.364  1.0
  O  O10  1  0.339  0.763  0.636  1.0
  O  O11  1  0.339  0.763  0.864  1.0
  O  O12  1  0.279  0.192  0.250  1.0
  O  O13  1  0.808  0.721  0.750  1.0
  O  O14  1  0.828  0.742  0.535  1.0
  O  O15  1  0.828  0.742  0.965  1.0
  O  O16  1  0.258  0.172  0.035  1.0
  O  O17  1  0.258  0.172  0.465  1.0
  O  O18  1  0.848  0.253  0.865  1.0
  O  O19  1  0.848  0.253  0.635  1.0
  O  O20  1  0.747  0.152  0.135  1.0
  O  O21  1  0.747  0.152  0.365  1.0
[/CIF]
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