The crystal structure described by Sr2YI7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one I(1), one I(3), one I(4), one I(5), one I(7), two equivalent I(2), and two equivalent I(6) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and two equivalent I(7) atoms. Y(1) is bonded in a distorted pentagonal bipyramidal geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and one I(7) atom. There are seven inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the second I site, I(2) is bonded to one Sr(2), two equivalent Sr(1), and one Y(1) atom to form a mixture of distorted edge and corner-sharing ISr3Y tetrahedra. In the third I site, I(3) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the fourth I site, I(4) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the fifth I site, I(5) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the sixth I site, I(6) is bonded to one Sr(2), two equivalent Sr(1), and one Y(1) atom to form a mixture of edge and corner-sharing ISr3Y tetrahedra. In the seventh I site, I(7) is bonded to one Sr(1), two equivalent Sr(2), and one Y(1) atom to form a mixture of edge and corner-sharing ISr3Y tetrahedra. is represented by the CIF file [CIF]
data_Sr2YI7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   17.305
_cell_length_b   7.807
_cell_length_c   11.965
_cell_angle_alpha   89.357
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1616.463
_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  0.557  0.279  0.675  1.0
  Sr  Sr1  1  0.219  0.286  0.549  1.0
  Sr  Sr2  1  0.943  0.279  0.175  1.0
  Sr  Sr3  1  0.281  0.286  0.049  1.0
  Sr  Sr4  1  0.719  0.714  0.951  1.0
  Sr  Sr5  1  0.057  0.721  0.825  1.0
  Sr  Sr6  1  0.781  0.714  0.451  1.0
  Sr  Sr7  1  0.443  0.721  0.325  1.0
  Y  Y8  1  0.868  0.217  0.722  1.0
  Y  Y9  1  0.632  0.217  0.222  1.0
  Y  Y10  1  0.368  0.783  0.778  1.0
  Y  Y11  1  0.132  0.783  0.278  1.0
  I  I12  1  0.215  0.996  0.780  1.0
  I  I13  1  0.397  0.004  0.564  1.0
  I  I14  1  0.285  0.996  0.280  1.0
  I  I15  1  0.103  0.004  0.064  1.0
  I  I16  1  0.427  0.135  0.878  1.0
  I  I17  1  0.073  0.135  0.378  1.0
  I  I18  1  0.642  0.307  0.972  1.0
  I  I19  1  0.858  0.307  0.472  1.0
  I  I20  1  0.039  0.316  0.710  1.0
  I  I21  1  0.461  0.316  0.210  1.0
  I  I22  1  0.894  0.493  0.924  1.0
  I  I23  1  0.738  0.503  0.700  1.0
  I  I24  1  0.606  0.493  0.424  1.0
  I  I25  1  0.762  0.503  0.200  1.0
  I  I26  1  0.238  0.497  0.800  1.0
  I  I27  1  0.394  0.507  0.576  1.0
  I  I28  1  0.262  0.497  0.300  1.0
  I  I29  1  0.106  0.507  0.076  1.0
  I  I30  1  0.539  0.684  0.790  1.0
  I  I31  1  0.961  0.684  0.290  1.0
  I  I32  1  0.142  0.693  0.528  1.0
  I  I33  1  0.358  0.693  0.028  1.0
  I  I34  1  0.927  0.865  0.622  1.0
  I  I35  1  0.573  0.865  0.122  1.0
  I  I36  1  0.897  0.996  0.936  1.0
  I  I37  1  0.715  0.004  0.720  1.0
  I  I38  1  0.603  0.996  0.436  1.0
  I  I39  1  0.785  0.004  0.220  1.0
[/CIF]
.
The crystal structure described by Sr2YI7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one I(1), one I(3), one I(4), one I(5), one I(7), two equivalent I(2), and two equivalent I(6) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and two equivalent I(7) atoms. Y(1) is bonded in a distorted pentagonal bipyramidal geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and one I(7) atom. There are seven inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the second I site, I(2) is bonded to one Sr(2), two equivalent Sr(1), and one Y(1) atom to form a mixture of distorted edge and corner-sharing ISr3Y tetrahedra. In the third I site, I(3) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the fourth I site, I(4) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the fifth I site, I(5) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one Y(1) atom. In the sixth I site, I(6) is bonded to one Sr(2), two equivalent Sr(1), and one Y(1) atom to form a mixture of edge and corner-sharing ISr3Y tetrahedra. In the seventh I site, I(7) is bonded to one Sr(1), two equivalent Sr(2), and one Y(1) atom to form a mixture of edge and corner-sharing ISr3Y tetrahedra. is represented by the CIF file [CIF]
data_Sr2YI7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   17.305
_cell_length_b   7.807
_cell_length_c   11.965
_cell_angle_alpha   89.357
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1616.463
_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  0.557  0.279  0.675  1.0
  Sr  Sr1  1  0.219  0.286  0.549  1.0
  Sr  Sr2  1  0.943  0.279  0.175  1.0
  Sr  Sr3  1  0.281  0.286  0.049  1.0
  Sr  Sr4  1  0.719  0.714  0.951  1.0
  Sr  Sr5  1  0.057  0.721  0.825  1.0
  Sr  Sr6  1  0.781  0.714  0.451  1.0
  Sr  Sr7  1  0.443  0.721  0.325  1.0
  Y  Y8  1  0.868  0.217  0.722  1.0
  Y  Y9  1  0.632  0.217  0.222  1.0
  Y  Y10  1  0.368  0.783  0.778  1.0
  Y  Y11  1  0.132  0.783  0.278  1.0
  I  I12  1  0.215  0.996  0.780  1.0
  I  I13  1  0.397  0.004  0.564  1.0
  I  I14  1  0.285  0.996  0.280  1.0
  I  I15  1  0.103  0.004  0.064  1.0
  I  I16  1  0.427  0.135  0.878  1.0
  I  I17  1  0.073  0.135  0.378  1.0
  I  I18  1  0.642  0.307  0.972  1.0
  I  I19  1  0.858  0.307  0.472  1.0
  I  I20  1  0.039  0.316  0.710  1.0
  I  I21  1  0.461  0.316  0.210  1.0
  I  I22  1  0.894  0.493  0.924  1.0
  I  I23  1  0.738  0.503  0.700  1.0
  I  I24  1  0.606  0.493  0.424  1.0
  I  I25  1  0.762  0.503  0.200  1.0
  I  I26  1  0.238  0.497  0.800  1.0
  I  I27  1  0.394  0.507  0.576  1.0
  I  I28  1  0.262  0.497  0.300  1.0
  I  I29  1  0.106  0.507  0.076  1.0
  I  I30  1  0.539  0.684  0.790  1.0
  I  I31  1  0.961  0.684  0.290  1.0
  I  I32  1  0.142  0.693  0.528  1.0
  I  I33  1  0.358  0.693  0.028  1.0
  I  I34  1  0.927  0.865  0.622  1.0
  I  I35  1  0.573  0.865  0.122  1.0
  I  I36  1  0.897  0.996  0.936  1.0
  I  I37  1  0.715  0.004  0.720  1.0
  I  I38  1  0.603  0.996  0.436  1.0
  I  I39  1  0.785  0.004  0.220  1.0
[/CIF]
.