The material structure described by Sr2Cr2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(12), one O(2), one O(5), one O(6), one O(7), and two equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(13), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(3), one O(5), and one O(6) atom. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(13), one O(14), one O(7), one O(8), and two equivalent O(9) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(11), one O(2), one O(3), and one O(6) atom to form corner-sharing CrO4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(1), one O(4), one O(7), and one O(9) atom to form corner-sharing CrO4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(13), one O(4), one O(5), and one O(8) atom to form corner-sharing CrO4 tetrahedra. In the fourth Cr site, Cr(4) is bonded to one O(10), one O(11), one O(12), and one O(14) atom to form corner-sharing CrO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Sr(1), one Sr(4), and one Cr(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Sr(1) and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Sr(3), two equivalent Sr(1), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Sr(2), one Cr(2), and one Cr(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(2), one Sr(3), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Cr(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(2), one Sr(4), and one Cr(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Sr(2), one Sr(4), and one Cr(3) atom. In the ninth O site, O(9) is bonded to one Sr(2), two equivalent Sr(4), and one Cr(2) atom to form distorted edge-sharing OSr3Cr tetrahedra. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(3), one Sr(4), and one Cr(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Sr(3), one Cr(1), and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Sr(1), one Sr(3), and one Cr(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), and one Cr(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Sr(3), one Sr(4), and one Cr(4) atom. is represented by the CIF card [CIF]
data_Sr2Cr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.126
_cell_length_b   7.213
_cell_length_c   13.081
_cell_angle_alpha   82.317
_cell_angle_beta   87.571
_cell_angle_gamma   88.862
_symmetry_Int_Tables_number   1
_cell_volume   665.557
_cell_formula_units_Z   4
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  0.076  0.846  0.156  1.0
  Sr  Sr1  1  0.235  0.225  0.351  1.0
  Sr  Sr2  1  0.331  0.764  0.860  1.0
  Sr  Sr3  1  0.373  0.376  0.638  1.0
  Sr  Sr4  1  0.627  0.624  0.362  1.0
  Sr  Sr5  1  0.669  0.236  0.140  1.0
  Sr  Sr6  1  0.765  0.775  0.649  1.0
  Sr  Sr7  1  0.924  0.154  0.844  1.0
  Cr  Cr8  1  0.155  0.313  0.089  1.0
  Cr  Cr9  1  0.164  0.695  0.408  1.0
  Cr  Cr10  1  0.230  0.897  0.608  1.0
  Cr  Cr11  1  0.432  0.283  0.894  1.0
  Cr  Cr12  1  0.568  0.717  0.106  1.0
  Cr  Cr13  1  0.770  0.103  0.392  1.0
  Cr  Cr14  1  0.836  0.305  0.592  1.0
  Cr  Cr15  1  0.845  0.687  0.911  1.0
  O  O16  1  0.015  0.374  0.656  1.0
  O  O17  1  0.065  0.478  0.154  1.0
  O  O18  1  0.006  0.831  0.952  1.0
  O  O19  1  0.083  0.785  0.526  1.0
  O  O20  1  0.076  0.917  0.712  1.0
  O  O21  1  0.307  0.170  0.166  1.0
  O  O22  1  0.302  0.853  0.337  1.0
  O  O23  1  0.301  0.102  0.544  1.0
  O  O24  1  0.310  0.503  0.445  1.0
  O  O25  1  0.291  0.145  0.835  1.0
  O  O26  1  0.296  0.419  0.978  1.0
  O  O27  1  0.378  0.814  0.046  1.0
  O  O28  1  0.403  0.747  0.656  1.0
  O  O29  1  0.503  0.537  0.199  1.0
  O  O30  1  0.497  0.463  0.801  1.0
  O  O31  1  0.597  0.253  0.344  1.0
  O  O32  1  0.622  0.186  0.954  1.0
  O  O33  1  0.704  0.581  0.022  1.0
  O  O34  1  0.709  0.855  0.165  1.0
  O  O35  1  0.690  0.497  0.555  1.0
  O  O36  1  0.699  0.898  0.456  1.0
  O  O37  1  0.698  0.147  0.663  1.0
  O  O38  1  0.693  0.830  0.834  1.0
  O  O39  1  0.924  0.083  0.288  1.0
  O  O40  1  0.917  0.215  0.474  1.0
  O  O41  1  0.994  0.169  0.048  1.0
  O  O42  1  0.935  0.522  0.846  1.0
  O  O43  1  0.985  0.626  0.344  1.0
[/CIF]
.
The material structure described by Sr2Cr2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(12), one O(2), one O(5), one O(6), one O(7), and two equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(13), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(12), one O(13), one O(14), one O(3), one O(5), and one O(6) atom. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(13), one O(14), one O(7), one O(8), and two equivalent O(9) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(11), one O(2), one O(3), and one O(6) atom to form corner-sharing CrO4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(1), one O(4), one O(7), and one O(9) atom to form corner-sharing CrO4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(13), one O(4), one O(5), and one O(8) atom to form corner-sharing CrO4 tetrahedra. In the fourth Cr site, Cr(4) is bonded to one O(10), one O(11), one O(12), and one O(14) atom to form corner-sharing CrO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Sr(1), one Sr(4), and one Cr(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Sr(1) and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Sr(3), two equivalent Sr(1), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Sr(2), one Cr(2), and one Cr(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(2), one Sr(3), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Cr(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(2), one Sr(4), and one Cr(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Sr(2), one Sr(4), and one Cr(3) atom. In the ninth O site, O(9) is bonded to one Sr(2), two equivalent Sr(4), and one Cr(2) atom to form distorted edge-sharing OSr3Cr tetrahedra. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Sr(1), one Sr(3), one Sr(4), and one Cr(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one Sr(3), one Cr(1), and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Sr(1), one Sr(3), and one Cr(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), and one Cr(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Sr(3), one Sr(4), and one Cr(4) atom. is represented by the CIF card [CIF]
data_Sr2Cr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.126
_cell_length_b   7.213
_cell_length_c   13.081
_cell_angle_alpha   82.317
_cell_angle_beta   87.571
_cell_angle_gamma   88.862
_symmetry_Int_Tables_number   1
_cell_volume   665.557
_cell_formula_units_Z   4
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  0.076  0.846  0.156  1.0
  Sr  Sr1  1  0.235  0.225  0.351  1.0
  Sr  Sr2  1  0.331  0.764  0.860  1.0
  Sr  Sr3  1  0.373  0.376  0.638  1.0
  Sr  Sr4  1  0.627  0.624  0.362  1.0
  Sr  Sr5  1  0.669  0.236  0.140  1.0
  Sr  Sr6  1  0.765  0.775  0.649  1.0
  Sr  Sr7  1  0.924  0.154  0.844  1.0
  Cr  Cr8  1  0.155  0.313  0.089  1.0
  Cr  Cr9  1  0.164  0.695  0.408  1.0
  Cr  Cr10  1  0.230  0.897  0.608  1.0
  Cr  Cr11  1  0.432  0.283  0.894  1.0
  Cr  Cr12  1  0.568  0.717  0.106  1.0
  Cr  Cr13  1  0.770  0.103  0.392  1.0
  Cr  Cr14  1  0.836  0.305  0.592  1.0
  Cr  Cr15  1  0.845  0.687  0.911  1.0
  O  O16  1  0.015  0.374  0.656  1.0
  O  O17  1  0.065  0.478  0.154  1.0
  O  O18  1  0.006  0.831  0.952  1.0
  O  O19  1  0.083  0.785  0.526  1.0
  O  O20  1  0.076  0.917  0.712  1.0
  O  O21  1  0.307  0.170  0.166  1.0
  O  O22  1  0.302  0.853  0.337  1.0
  O  O23  1  0.301  0.102  0.544  1.0
  O  O24  1  0.310  0.503  0.445  1.0
  O  O25  1  0.291  0.145  0.835  1.0
  O  O26  1  0.296  0.419  0.978  1.0
  O  O27  1  0.378  0.814  0.046  1.0
  O  O28  1  0.403  0.747  0.656  1.0
  O  O29  1  0.503  0.537  0.199  1.0
  O  O30  1  0.497  0.463  0.801  1.0
  O  O31  1  0.597  0.253  0.344  1.0
  O  O32  1  0.622  0.186  0.954  1.0
  O  O33  1  0.704  0.581  0.022  1.0
  O  O34  1  0.709  0.855  0.165  1.0
  O  O35  1  0.690  0.497  0.555  1.0
  O  O36  1  0.699  0.898  0.456  1.0
  O  O37  1  0.698  0.147  0.663  1.0
  O  O38  1  0.693  0.830  0.834  1.0
  O  O39  1  0.924  0.083  0.288  1.0
  O  O40  1  0.917  0.215  0.474  1.0
  O  O41  1  0.994  0.169  0.048  1.0
  O  O42  1  0.935  0.522  0.846  1.0
  O  O43  1  0.985  0.626  0.344  1.0
[/CIF]
.