The structure described by MgMn2(SeO3)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(12), one O(2), one O(6), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(1)O5 trigonal bipyramid, and  an edgeedge with one Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(11), one O(3), one O(7), and one O(9) atom to form distorted MnO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O5 trigonal bipyramid. In the second Mn site, Mn(2) is bonded to one O(10), one O(12), one O(2), one O(4), one O(5), and one O(8) atom to form MnO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one O(12), one O(3), and one O(8) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(11), one O(4), and one O(7) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(2), one O(6), and one O(9) atom. In the fourth Se site, Se(4) is bonded in a trigonal non-coplanar geometry to one O(1), one O(10), and one O(5) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Se(4) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Mn(2), and one Se(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(4) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Mg(1) and one Se(3) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mn(2), and one Se(1) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(4) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(2) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Mg(1), one Mn(2), and one Se(1) atom. is represented by the CIF card [CIF]
data_MgMn2(SeO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.445
_cell_length_b   6.895
_cell_length_c   7.892
_cell_angle_alpha   88.698
_cell_angle_beta   93.249
_cell_angle_gamma   83.756
_symmetry_Int_Tables_number   1
_cell_volume   293.887
_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  0.545  0.279  0.848  1.0
  Mn  Mn1  1  0.529  0.515  0.482  1.0
  Mn  Mn2  1  0.998  0.998  0.996  1.0
  Se  Se3  1  0.506  0.172  0.200  1.0
  Se  Se4  1  0.994  0.682  0.303  1.0
  Se  Se5  1  0.023  0.340  0.682  1.0
  Se  Se6  1  0.485  0.800  0.802  1.0
  O  O7  1  0.559  0.549  0.742  1.0
  O  O8  1  0.882  0.142  0.776  1.0
  O  O9  1  0.430  0.406  0.265  1.0
  O  O10  1  0.067  0.909  0.229  1.0
  O  O11  1  0.213  0.778  0.899  1.0
  O  O12  1  0.308  0.230  0.639  1.0
  O  O13  1  0.210  0.660  0.483  1.0
  O  O14  1  0.304  0.187  0.018  1.0
  O  O15  1  0.842  0.339  0.493  1.0
  O  O16  1  0.691  0.818  0.969  1.0
  O  O17  1  0.731  0.746  0.406  1.0
  O  O18  1  0.757  0.219  0.080  1.0
[/CIF]
.
The structure described by MgMn2(SeO3)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(12), one O(2), one O(6), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(1)O5 trigonal bipyramid, and  an edgeedge with one Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(11), one O(3), one O(7), and one O(9) atom to form distorted MnO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O5 trigonal bipyramid. In the second Mn site, Mn(2) is bonded to one O(10), one O(12), one O(2), one O(4), one O(5), and one O(8) atom to form MnO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one O(12), one O(3), and one O(8) atom. In the second Se site, Se(2) is bonded in a distorted trigonal non-coplanar geometry to one O(11), one O(4), and one O(7) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(2), one O(6), and one O(9) atom. In the fourth Se site, Se(4) is bonded in a trigonal non-coplanar geometry to one O(1), one O(10), and one O(5) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mn(1), and one Se(4) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Mg(1), one Mn(2), and one Se(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(4) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Mg(1) and one Se(3) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mn(2), and one Se(1) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Mn(2) and one Se(4) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Mn(1) and one Se(2) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Mg(1), one Mn(2), and one Se(1) atom. is represented by the CIF card [CIF]
data_MgMn2(SeO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.445
_cell_length_b   6.895
_cell_length_c   7.892
_cell_angle_alpha   88.698
_cell_angle_beta   93.249
_cell_angle_gamma   83.756
_symmetry_Int_Tables_number   1
_cell_volume   293.887
_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  0.545  0.279  0.848  1.0
  Mn  Mn1  1  0.529  0.515  0.482  1.0
  Mn  Mn2  1  0.998  0.998  0.996  1.0
  Se  Se3  1  0.506  0.172  0.200  1.0
  Se  Se4  1  0.994  0.682  0.303  1.0
  Se  Se5  1  0.023  0.340  0.682  1.0
  Se  Se6  1  0.485  0.800  0.802  1.0
  O  O7  1  0.559  0.549  0.742  1.0
  O  O8  1  0.882  0.142  0.776  1.0
  O  O9  1  0.430  0.406  0.265  1.0
  O  O10  1  0.067  0.909  0.229  1.0
  O  O11  1  0.213  0.778  0.899  1.0
  O  O12  1  0.308  0.230  0.639  1.0
  O  O13  1  0.210  0.660  0.483  1.0
  O  O14  1  0.304  0.187  0.018  1.0
  O  O15  1  0.842  0.339  0.493  1.0
  O  O16  1  0.691  0.818  0.969  1.0
  O  O17  1  0.731  0.746  0.406  1.0
  O  O18  1  0.757  0.219  0.080  1.0
[/CIF]
.