The structure described by LiMn2Si2O7 crystallizes in the monoclinic Cc space group. Li(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and corners with two equivalent Mn(1)O5 trigonal bipyramids. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(7) atom to form MnO5 trigonal bipyramids that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. In the second Mn site, Mn(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Mn(1)O5 trigonal bipyramids, and corners with three equivalent Li(1)O4 trigonal pyramids. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Mn(1)O5 trigonal bipyramids, and  a cornercorner with one Li(1)O4 trigonal pyramid. There are seven inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one Si(1) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(2) atom. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Mn(1), one Mn(2), and one Si(1) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(1), one Si(1), and one Si(2) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(2), and one Si(2) atom. In the sixth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Mn(2), and one Si(1) atom. In the seventh O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1), one Mn(2), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_LiMn2Si2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.931
_cell_length_b   4.931
_cell_length_c   13.629
_cell_angle_alpha   91.144
_cell_angle_beta   88.859
_cell_angle_gamma   63.413
_symmetry_Int_Tables_number   1
_cell_volume   296.131
_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
  Li  Li0  1  0.349  0.285  0.915  1.0
  Li  Li1  1  0.715  0.651  0.415  1.0
  Mn  Mn2  1  0.989  0.950  0.255  1.0
  Mn  Mn3  1  0.050  0.011  0.755  1.0
  Mn  Mn4  1  0.048  0.949  0.019  1.0
  Mn  Mn5  1  0.051  0.953  0.519  1.0
  Si  Si6  1  0.714  0.638  0.855  1.0
  Si  Si7  1  0.361  0.286  0.355  1.0
  Si  Si8  1  0.712  0.600  0.642  1.0
  Si  Si9  1  0.400  0.288  0.142  1.0
  O  O10  1  0.201  0.658  0.151  1.0
  O  O11  1  0.342  0.798  0.651  1.0
  O  O12  1  0.104  0.647  0.359  1.0
  O  O13  1  0.353  0.896  0.859  1.0
  O  O14  1  0.322  0.144  0.244  1.0
  O  O15  1  0.856  0.678  0.744  1.0
  O  O16  1  0.856  0.661  0.544  1.0
  O  O17  1  0.339  0.144  0.044  1.0
  O  O18  1  0.937  0.668  0.933  1.0
  O  O19  1  0.332  0.063  0.433  1.0
  O  O20  1  0.804  0.235  0.647  1.0
  O  O21  1  0.765  0.196  0.147  1.0
  O  O22  1  0.739  0.292  0.852  1.0
  O  O23  1  0.708  0.262  0.352  1.0
[/CIF]
.
The structure described by LiMn2Si2O7 crystallizes in the monoclinic Cc space group. Li(1) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form distorted LiO4 trigonal pyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and corners with two equivalent Mn(1)O5 trigonal bipyramids. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(7) atom to form MnO5 trigonal bipyramids that share corners with three equivalent Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and corners with two equivalent Li(1)O4 trigonal pyramids. In the second Mn site, Mn(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra, corners with three equivalent Mn(1)O5 trigonal bipyramids, and corners with three equivalent Li(1)O4 trigonal pyramids. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Mn(1)O5 trigonal bipyramids, and  a cornercorner with one Li(1)O4 trigonal pyramid. There are seven inequivalent O sites. In the first O site, O(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(1), and one Si(1) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(2) atom. In the third O site, O(2) is bonded in a 4-coordinate geometry to one Li(1), one Mn(1), one Mn(2), and one Si(1) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to one Mn(1), one Si(1), and one Si(2) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Li(1), one Mn(2), and one Si(2) atom. In the sixth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Mn(2), and one Si(1) atom. In the seventh O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1), one Mn(2), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_LiMn2Si2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.931
_cell_length_b   4.931
_cell_length_c   13.629
_cell_angle_alpha   91.144
_cell_angle_beta   88.859
_cell_angle_gamma   63.413
_symmetry_Int_Tables_number   1
_cell_volume   296.131
_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
  Li  Li0  1  0.349  0.285  0.915  1.0
  Li  Li1  1  0.715  0.651  0.415  1.0
  Mn  Mn2  1  0.989  0.950  0.255  1.0
  Mn  Mn3  1  0.050  0.011  0.755  1.0
  Mn  Mn4  1  0.048  0.949  0.019  1.0
  Mn  Mn5  1  0.051  0.953  0.519  1.0
  Si  Si6  1  0.714  0.638  0.855  1.0
  Si  Si7  1  0.361  0.286  0.355  1.0
  Si  Si8  1  0.712  0.600  0.642  1.0
  Si  Si9  1  0.400  0.288  0.142  1.0
  O  O10  1  0.201  0.658  0.151  1.0
  O  O11  1  0.342  0.798  0.651  1.0
  O  O12  1  0.104  0.647  0.359  1.0
  O  O13  1  0.353  0.896  0.859  1.0
  O  O14  1  0.322  0.144  0.244  1.0
  O  O15  1  0.856  0.678  0.744  1.0
  O  O16  1  0.856  0.661  0.544  1.0
  O  O17  1  0.339  0.144  0.044  1.0
  O  O18  1  0.937  0.668  0.933  1.0
  O  O19  1  0.332  0.063  0.433  1.0
  O  O20  1  0.804  0.235  0.647  1.0
  O  O21  1  0.765  0.196  0.147  1.0
  O  O22  1  0.739  0.292  0.852  1.0
  O  O23  1  0.708  0.262  0.352  1.0
[/CIF]
.