The compound described by BaSr2Mn2(Si2O7)2 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Sr(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(3) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with four equivalent Si(2)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 two 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(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(6), and one O(7) 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(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-68°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Sr(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Sr(1), one Mn(1), and one Mn(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ba(1), one Sr(1), one Mn(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), one Mn(1), one Mn(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_BaSr2Mn2(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.400
_cell_length_b   8.400
_cell_length_c   5.236
_cell_angle_alpha   87.165
_cell_angle_beta   87.165
_cell_angle_gamma   55.909
_symmetry_Int_Tables_number   1
_cell_volume   305.450
_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
  Ba  Ba0  1  0.776  0.224  0.000  1.0
  Sr  Sr1  1  0.301  0.106  0.019  1.0
  Sr  Sr2  1  0.894  0.699  0.981  1.0
  Mn  Mn3  1  0.304  0.696  0.000  1.0
  Mn  Mn4  1  0.110  0.890  0.500  1.0
  Si  Si5  1  0.629  0.023  0.513  1.0
  Si  Si6  1  0.977  0.371  0.487  1.0
  Si  Si7  1  0.557  0.705  0.539  1.0
  Si  Si8  1  0.295  0.443  0.461  1.0
  O  O9  1  0.589  0.866  0.670  1.0
  O  O10  1  0.134  0.411  0.330  1.0
  O  O11  1  0.542  0.584  0.780  1.0
  O  O12  1  0.416  0.458  0.220  1.0
  O  O13  1  0.993  0.376  0.791  1.0
  O  O14  1  0.624  0.007  0.209  1.0
  O  O15  1  0.186  0.935  0.808  1.0
  O  O16  1  0.065  0.814  0.192  1.0
  O  O17  1  0.821  0.985  0.635  1.0
  O  O18  1  0.387  0.811  0.332  1.0
  O  O19  1  0.189  0.613  0.668  1.0
  O  O20  1  0.766  0.559  0.378  1.0
  O  O21  1  0.441  0.234  0.622  1.0
  O  O22  1  0.015  0.179  0.365  1.0
[/CIF]
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The compound described by BaSr2Mn2(Si2O7)2 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Sr(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), one O(6), one O(7), two equivalent O(1), and two equivalent O(3) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form MnO6 octahedra that share corners with four equivalent Si(2)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 two 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(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Mn(2)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(6), and one O(7) 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(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-68°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Sr(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Sr(1), one Mn(1), and one Mn(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ba(1), one Sr(1), one Mn(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(1), one Mn(1), one Mn(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_BaSr2Mn2(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.400
_cell_length_b   8.400
_cell_length_c   5.236
_cell_angle_alpha   87.165
_cell_angle_beta   87.165
_cell_angle_gamma   55.909
_symmetry_Int_Tables_number   1
_cell_volume   305.450
_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
  Ba  Ba0  1  0.776  0.224  0.000  1.0
  Sr  Sr1  1  0.301  0.106  0.019  1.0
  Sr  Sr2  1  0.894  0.699  0.981  1.0
  Mn  Mn3  1  0.304  0.696  0.000  1.0
  Mn  Mn4  1  0.110  0.890  0.500  1.0
  Si  Si5  1  0.629  0.023  0.513  1.0
  Si  Si6  1  0.977  0.371  0.487  1.0
  Si  Si7  1  0.557  0.705  0.539  1.0
  Si  Si8  1  0.295  0.443  0.461  1.0
  O  O9  1  0.589  0.866  0.670  1.0
  O  O10  1  0.134  0.411  0.330  1.0
  O  O11  1  0.542  0.584  0.780  1.0
  O  O12  1  0.416  0.458  0.220  1.0
  O  O13  1  0.993  0.376  0.791  1.0
  O  O14  1  0.624  0.007  0.209  1.0
  O  O15  1  0.186  0.935  0.808  1.0
  O  O16  1  0.065  0.814  0.192  1.0
  O  O17  1  0.821  0.985  0.635  1.0
  O  O18  1  0.387  0.811  0.332  1.0
  O  O19  1  0.189  0.613  0.668  1.0
  O  O20  1  0.766  0.559  0.378  1.0
  O  O21  1  0.441  0.234  0.622  1.0
  O  O22  1  0.015  0.179  0.365  1.0
[/CIF]
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