The material structure described by SrMgCr(PO4)2 is Esseneite-derived structured and crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms. Cr(1) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms to form distorted CrO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-62°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sr(1), one Mg(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Mg(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Cr(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mg(1), one Cr(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Cr(1), and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrMgCr(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.659
_cell_length_b   6.848
_cell_length_c   9.375
_cell_angle_alpha   109.700
_cell_angle_beta   102.230
_cell_angle_gamma   98.620
_symmetry_Int_Tables_number   1
_cell_volume   324.488
_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
  Sr  Sr0  1  0.257  0.802  0.055  1.0
  Sr  Sr1  1  0.743  0.198  0.945  1.0
  Mg  Mg2  1  0.993  0.392  0.648  1.0
  Mg  Mg3  1  0.007  0.608  0.352  1.0
  Cr  Cr4  1  0.641  0.844  0.548  1.0
  Cr  Cr5  1  0.359  0.156  0.452  1.0
  P  P6  1  0.391  0.423  0.235  1.0
  P  P7  1  0.609  0.577  0.765  1.0
  P  P8  1  0.838  0.023  0.298  1.0
  P  P9  1  0.162  0.977  0.702  1.0
  O  O10  1  0.821  0.555  0.890  1.0
  O  O11  1  0.653  0.478  0.213  1.0
  O  O12  1  0.662  0.802  0.760  1.0
  O  O13  1  0.953  0.108  0.688  1.0
  O  O14  1  0.347  0.522  0.787  1.0
  O  O15  1  0.036  0.741  0.586  1.0
  O  O16  1  0.964  0.259  0.414  1.0
  O  O17  1  0.262  0.002  0.873  1.0
  O  O18  1  0.338  0.198  0.240  1.0
  O  O19  1  0.738  0.998  0.127  1.0
  O  O20  1  0.179  0.445  0.110  1.0
  O  O21  1  0.367  0.584  0.395  1.0
  O  O22  1  0.633  0.416  0.605  1.0
  O  O23  1  0.621  0.929  0.353  1.0
  O  O24  1  0.047  0.892  0.312  1.0
  O  O25  1  0.379  0.071  0.647  1.0
[/CIF]
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The material structure described by SrMgCr(PO4)2 is Esseneite-derived structured and crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms. Cr(1) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms to form distorted CrO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Cr(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and  an edgeedge with one Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-62°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sr(1), one Mg(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Mg(1), one Cr(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Cr(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mg(1), one Cr(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Cr(1), and one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrMgCr(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.659
_cell_length_b   6.848
_cell_length_c   9.375
_cell_angle_alpha   109.700
_cell_angle_beta   102.230
_cell_angle_gamma   98.620
_symmetry_Int_Tables_number   1
_cell_volume   324.488
_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
  Sr  Sr0  1  0.257  0.802  0.055  1.0
  Sr  Sr1  1  0.743  0.198  0.945  1.0
  Mg  Mg2  1  0.993  0.392  0.648  1.0
  Mg  Mg3  1  0.007  0.608  0.352  1.0
  Cr  Cr4  1  0.641  0.844  0.548  1.0
  Cr  Cr5  1  0.359  0.156  0.452  1.0
  P  P6  1  0.391  0.423  0.235  1.0
  P  P7  1  0.609  0.577  0.765  1.0
  P  P8  1  0.838  0.023  0.298  1.0
  P  P9  1  0.162  0.977  0.702  1.0
  O  O10  1  0.821  0.555  0.890  1.0
  O  O11  1  0.653  0.478  0.213  1.0
  O  O12  1  0.662  0.802  0.760  1.0
  O  O13  1  0.953  0.108  0.688  1.0
  O  O14  1  0.347  0.522  0.787  1.0
  O  O15  1  0.036  0.741  0.586  1.0
  O  O16  1  0.964  0.259  0.414  1.0
  O  O17  1  0.262  0.002  0.873  1.0
  O  O18  1  0.338  0.198  0.240  1.0
  O  O19  1  0.738  0.998  0.127  1.0
  O  O20  1  0.179  0.445  0.110  1.0
  O  O21  1  0.367  0.584  0.395  1.0
  O  O22  1  0.633  0.416  0.605  1.0
  O  O23  1  0.621  0.929  0.353  1.0
  O  O24  1  0.047  0.892  0.312  1.0
  O  O25  1  0.379  0.071  0.647  1.0
[/CIF]
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