The material structure described by MgMn4(Si4O11)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(11), one O(7), one O(8), and one O(9) atom to form distorted MnO5 trigonal bipyramids that share corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and  an edgeedge with one Mn(2)O5 square pyramid. In the second Mn site, Mn(2) is bonded to one O(11), one O(3), one O(7), one O(8), and one O(9) atom to form distorted MnO5 square pyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, corners with two equivalent Mn(1)O5 trigonal bipyramids, and  an edgeedge with one Mn(1)O5 trigonal bipyramid. There are four 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(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Mn(1)O5 trigonal bipyramid. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Mn(1)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Mn(1)O5 trigonal bipyramid. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Mn(1)O5 trigonal bipyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) 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_MgMn4(Si4O11)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.752
_cell_length_b   7.753
_cell_length_c   7.152
_cell_angle_alpha   108.497
_cell_angle_beta   101.810
_cell_angle_gamma   99.979
_symmetry_Int_Tables_number   1
_cell_volume   435.410
_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  0.000  0.500  0.000  1.0
  Mn  Mn1  1  0.376  0.658  0.852  1.0
  Mn  Mn2  1  0.401  0.620  0.346  1.0
  Mn  Mn3  1  0.599  0.380  0.654  1.0
  Mn  Mn4  1  0.624  0.342  0.148  1.0
  Si  Si5  1  0.041  0.354  0.257  1.0
  Si  Si6  1  0.238  0.203  0.969  1.0
  Si  Si7  1  0.222  0.204  0.535  1.0
  Si  Si8  1  0.605  0.982  0.758  1.0
  Si  Si9  1  0.395  0.018  0.242  1.0
  Si  Si10  1  0.778  0.796  0.465  1.0
  Si  Si11  1  0.762  0.797  0.031  1.0
  Si  Si12  1  0.959  0.646  0.743  1.0
  O  O13  1  0.129  0.600  0.825  1.0
  O  O14  1  0.060  0.252  0.421  1.0
  O  O15  1  0.170  0.557  0.302  1.0
  O  O16  1  0.070  0.223  0.036  1.0
  O  O17  1  0.183  0.150  0.723  1.0
  O  O18  1  0.263  0.027  0.377  1.0
  O  O19  1  0.371  0.393  0.608  1.0
  O  O20  1  0.449  0.796  0.637  1.0
  O  O21  1  0.430  0.811  0.182  1.0
  O  O22  1  0.309  0.037  0.021  1.0
  O  O23  1  0.376  0.403  0.092  1.0
  O  O24  1  0.624  0.597  0.908  1.0
  O  O25  1  0.691  0.963  0.979  1.0
  O  O26  1  0.570  0.189  0.818  1.0
  O  O27  1  0.551  0.204  0.363  1.0
  O  O28  1  0.629  0.607  0.392  1.0
  O  O29  1  0.737  0.973  0.623  1.0
  O  O30  1  0.817  0.850  0.277  1.0
  O  O31  1  0.930  0.777  0.964  1.0
  O  O32  1  0.830  0.443  0.698  1.0
  O  O33  1  0.940  0.748  0.579  1.0
  O  O34  1  0.871  0.400  0.175  1.0
[/CIF]
.
The material structure described by MgMn4(Si4O11)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(11), one O(7), one O(8), and one O(9) atom to form distorted MnO5 trigonal bipyramids that share corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, and  an edgeedge with one Mn(2)O5 square pyramid. In the second Mn site, Mn(2) is bonded to one O(11), one O(3), one O(7), one O(8), and one O(9) atom to form distorted MnO5 square pyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, corners with two equivalent Si(4)O4 tetrahedra, corners with two equivalent Mn(1)O5 trigonal bipyramids, and  an edgeedge with one Mn(1)O5 trigonal bipyramid. There are four 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(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Mn(1)O5 trigonal bipyramid. In the second Si site, Si(2) is bonded to one O(10), one O(11), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Mn(1)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O5 square pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Mn(1)O5 trigonal bipyramid. In the fourth Si site, Si(4) is bonded to one O(10), one O(6), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Mn(2)O5 square pyramids,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Mn(1)O5 trigonal bipyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mg(1), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(3) and one Si(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(4) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(4) atom. In the eleventh O site, O(11) 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_MgMn4(Si4O11)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.752
_cell_length_b   7.753
_cell_length_c   7.152
_cell_angle_alpha   108.497
_cell_angle_beta   101.810
_cell_angle_gamma   99.979
_symmetry_Int_Tables_number   1
_cell_volume   435.410
_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  0.000  0.500  0.000  1.0
  Mn  Mn1  1  0.376  0.658  0.852  1.0
  Mn  Mn2  1  0.401  0.620  0.346  1.0
  Mn  Mn3  1  0.599  0.380  0.654  1.0
  Mn  Mn4  1  0.624  0.342  0.148  1.0
  Si  Si5  1  0.041  0.354  0.257  1.0
  Si  Si6  1  0.238  0.203  0.969  1.0
  Si  Si7  1  0.222  0.204  0.535  1.0
  Si  Si8  1  0.605  0.982  0.758  1.0
  Si  Si9  1  0.395  0.018  0.242  1.0
  Si  Si10  1  0.778  0.796  0.465  1.0
  Si  Si11  1  0.762  0.797  0.031  1.0
  Si  Si12  1  0.959  0.646  0.743  1.0
  O  O13  1  0.129  0.600  0.825  1.0
  O  O14  1  0.060  0.252  0.421  1.0
  O  O15  1  0.170  0.557  0.302  1.0
  O  O16  1  0.070  0.223  0.036  1.0
  O  O17  1  0.183  0.150  0.723  1.0
  O  O18  1  0.263  0.027  0.377  1.0
  O  O19  1  0.371  0.393  0.608  1.0
  O  O20  1  0.449  0.796  0.637  1.0
  O  O21  1  0.430  0.811  0.182  1.0
  O  O22  1  0.309  0.037  0.021  1.0
  O  O23  1  0.376  0.403  0.092  1.0
  O  O24  1  0.624  0.597  0.908  1.0
  O  O25  1  0.691  0.963  0.979  1.0
  O  O26  1  0.570  0.189  0.818  1.0
  O  O27  1  0.551  0.204  0.363  1.0
  O  O28  1  0.629  0.607  0.392  1.0
  O  O29  1  0.737  0.973  0.623  1.0
  O  O30  1  0.817  0.850  0.277  1.0
  O  O31  1  0.930  0.777  0.964  1.0
  O  O32  1  0.830  0.443  0.698  1.0
  O  O33  1  0.940  0.748  0.579  1.0
  O  O34  1  0.871  0.400  0.175  1.0
[/CIF]
.