The crystal structure described by Sr2MgCrO4 crystallizes in the monoclinic Pm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), and four equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(4), and four equivalent O(1) atoms. Mg(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form MgO5 trigonal bipyramids that share corners with four equivalent Mg(1)O5 trigonal bipyramids and edges with four equivalent Cr(1)O5 trigonal bipyramids. Cr(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted CrO5 trigonal bipyramids that share corners with four equivalent Cr(1)O5 trigonal bipyramids and edges with four equivalent Mg(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Sr(2), and one Cr(1) atom to form OSr5Cr octahedra that share corners with four equivalent O(3)Sr2Mg2Cr2 octahedra, corners with four equivalent O(1)Sr5Cr octahedra, edges with four equivalent O(1)Sr5Cr octahedra, and edges with four equivalent O(2)Sr5Mg octahedra. The corner-sharing octahedral tilt angles range from 5-61°. In the second O site, O(2) is bonded to one Sr(2), four equivalent Sr(1), and one Mg(1) atom to form OSr5Mg octahedra that share corners with four equivalent O(3)Sr2Mg2Cr2 octahedra, corners with four equivalent O(2)Sr5Mg octahedra, edges with four equivalent O(1)Sr5Cr octahedra, edges with four equivalent O(2)Sr5Mg octahedra, and faces with two equivalent O(3)Sr2Mg2Cr2 octahedra. The corner-sharing octahedral tilt angles range from 5-63°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Mg(1), and two equivalent Cr(1) atoms to form distorted OSr2Mg2Cr2 octahedra that share corners with two equivalent O(3)Sr2Mg2Cr2 octahedra, corners with four equivalent O(1)Sr5Cr octahedra, corners with four equivalent O(2)Sr5Mg octahedra, edges with two equivalent O(3)Sr2Mg2Cr2 octahedra, and faces with two equivalent O(2)Sr5Mg octahedra. The corner-sharing octahedral tilt angles range from 6-63°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Mg(1), and two equivalent Cr(1) atoms. is represented by the CIF file [CIF]
data_Sr2MgCrO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.044
_cell_length_b   3.510
_cell_length_c   9.604
_cell_angle_alpha   110.863
_cell_angle_beta   114.902
_cell_angle_gamma   89.921
_symmetry_Int_Tables_number   1
_cell_volume   113.748
_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
  Sr  Sr0  1  0.498  0.493  0.354  1.0
  Sr  Sr1  1  0.320  0.323  0.675  1.0
  Mg  Mg2  1  0.753  0.763  0.109  1.0
  Cr  Cr3  1  0.069  0.112  0.924  1.0
  O  O4  1  0.812  0.783  0.666  1.0
  O  O5  1  0.014  0.017  0.369  1.0
  O  O6  1  0.249  0.728  0.104  1.0
  O  O7  1  0.602  0.115  0.957  1.0
[/CIF]
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The crystal structure described by Sr2MgCrO4 crystallizes in the monoclinic Pm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), and four equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(4), and four equivalent O(1) atoms. Mg(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form MgO5 trigonal bipyramids that share corners with four equivalent Mg(1)O5 trigonal bipyramids and edges with four equivalent Cr(1)O5 trigonal bipyramids. Cr(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted CrO5 trigonal bipyramids that share corners with four equivalent Cr(1)O5 trigonal bipyramids and edges with four equivalent Mg(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Sr(2), and one Cr(1) atom to form OSr5Cr octahedra that share corners with four equivalent O(3)Sr2Mg2Cr2 octahedra, corners with four equivalent O(1)Sr5Cr octahedra, edges with four equivalent O(1)Sr5Cr octahedra, and edges with four equivalent O(2)Sr5Mg octahedra. The corner-sharing octahedral tilt angles range from 5-61°. In the second O site, O(2) is bonded to one Sr(2), four equivalent Sr(1), and one Mg(1) atom to form OSr5Mg octahedra that share corners with four equivalent O(3)Sr2Mg2Cr2 octahedra, corners with four equivalent O(2)Sr5Mg octahedra, edges with four equivalent O(1)Sr5Cr octahedra, edges with four equivalent O(2)Sr5Mg octahedra, and faces with two equivalent O(3)Sr2Mg2Cr2 octahedra. The corner-sharing octahedral tilt angles range from 5-63°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Mg(1), and two equivalent Cr(1) atoms to form distorted OSr2Mg2Cr2 octahedra that share corners with two equivalent O(3)Sr2Mg2Cr2 octahedra, corners with four equivalent O(1)Sr5Cr octahedra, corners with four equivalent O(2)Sr5Mg octahedra, edges with two equivalent O(3)Sr2Mg2Cr2 octahedra, and faces with two equivalent O(2)Sr5Mg octahedra. The corner-sharing octahedral tilt angles range from 6-63°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Mg(1), and two equivalent Cr(1) atoms. is represented by the CIF file [CIF]
data_Sr2MgCrO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.044
_cell_length_b   3.510
_cell_length_c   9.604
_cell_angle_alpha   110.863
_cell_angle_beta   114.902
_cell_angle_gamma   89.921
_symmetry_Int_Tables_number   1
_cell_volume   113.748
_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
  Sr  Sr0  1  0.498  0.493  0.354  1.0
  Sr  Sr1  1  0.320  0.323  0.675  1.0
  Mg  Mg2  1  0.753  0.763  0.109  1.0
  Cr  Cr3  1  0.069  0.112  0.924  1.0
  O  O4  1  0.812  0.783  0.666  1.0
  O  O5  1  0.014  0.017  0.369  1.0
  O  O6  1  0.249  0.728  0.104  1.0
  O  O7  1  0.602  0.115  0.957  1.0
[/CIF]
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