The crystal structure described by Sr2GaAlSn2O7 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(3), one O(7), and two equivalent O(12) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(8), one O(9), and two equivalent O(10) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(1), one O(12), one O(13), one O(14), one O(2), one O(3), and two equivalent O(11) atoms. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one O(10), one O(5), one O(6), one O(7), one O(8), one O(9), and two equivalent O(4) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(10), one O(11), one O(2), and one O(7) atom to form corner-sharing GaO4 tetrahedra. In the second Ga site, Ga(2) is bonded to one O(12), one O(2), one O(4), and one O(7) atom to form corner-sharing GaO4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted water-like geometry to one O(1) and one O(3) atom. In the second Al site, Al(2) is bonded in a distorted water-like geometry to one Sn(2), one O(8), and one O(9) atom. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to one O(10), one O(5), one O(6), one O(8), and one O(9) atom. In the second Sn site, Sn(2) is bonded in a 6-coordinate geometry to one Al(2), one O(1), one O(11), one O(13), one O(14), and one O(3) atom. In the third Sn site, Sn(3) is bonded in a 3-coordinate geometry to one O(4), one O(5), and one O(6) atom. In the fourth Sn site, Sn(4) is bonded in a 3-coordinate geometry to one O(12), one O(13), and one O(14) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(3), one Al(1), and one Sn(2) atom. In the second O site, O(2) is bonded to one Sr(2), one Sr(3), one Ga(1), and one Ga(2) atom to form distorted OSr2Ga2 tetrahedra that share corners with two equivalent O(7)Sr2Ga2 tetrahedra,  a cornercorner with one O(13)Sr2Sn2 trigonal pyramid, and  a cornercorner with one O(6)Sr2Sn2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(3), one Al(1), and one Sn(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(2), two equivalent Sr(4), one Ga(2), and one Sn(3) atom. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to one Sr(2), one Sr(4), one Sn(1), and one Sn(3) atom. In the sixth O site, O(6) is bonded to one Sr(2), one Sr(4), one Sn(1), and one Sn(3) atom to form distorted corner-sharing OSr2Sn2 trigonal pyramids. In the seventh O site, O(7) is bonded to one Sr(1), one Sr(4), one Ga(1), and one Ga(2) atom to form OSr2Ga2 tetrahedra that share corners with two equivalent O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(13)Sr2Sn2 trigonal pyramid, and  a cornercorner with one O(6)Sr2Sn2 trigonal pyramid. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), one Al(2), and one Sn(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Sr(2), one Sr(4), one Al(2), and one Sn(1) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Sr(4), two equivalent Sr(2), one Ga(1), and one Sn(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(3), one Ga(1), and one Sn(2) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Sr(3), two equivalent Sr(1), one Ga(2), and one Sn(4) atom. In the thirteenth O site, O(13) is bonded to one Sr(1), one Sr(3), one Sn(2), and one Sn(4) atom to form distorted corner-sharing OSr2Sn2 trigonal pyramids. In the fourteenth O site, O(14) is bonded in a distorted see-saw-like geometry to one Sr(1), one Sr(3), one Sn(2), and one Sn(4) atom. is represented by the CIF card [CIF]
data_Sr2AlGaSn2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.753
_cell_length_b   6.585
_cell_length_c   12.198
_cell_angle_alpha   105.534
_cell_angle_beta   103.544
_cell_angle_gamma   89.883
_symmetry_Int_Tables_number   1
_cell_volume   431.937
_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  0.152  0.229  0.322  1.0
  Sr  Sr1  1  0.832  0.793  0.675  1.0
  Sr  Sr2  1  0.659  0.621  0.327  1.0
  Sr  Sr3  1  0.329  0.406  0.679  1.0
  Al  Al4  1  0.543  0.296  0.065  1.0
  Al  Al5  1  0.981  0.731  0.938  1.0
  Ga  Ga6  1  0.210  0.847  0.499  1.0
  Ga  Ga7  1  0.700  0.157  0.501  1.0
  Sn  Sn8  1  0.428  0.000  0.849  1.0
  Sn  Sn9  1  0.084  0.653  0.158  1.0
  Sn  Sn10  1  0.901  0.325  0.807  1.0
  Sn  Sn11  1  0.598  0.022  0.194  1.0
  O  O12  1  0.830  0.408  0.144  1.0
  O  O13  1  0.873  0.913  0.501  1.0
  O  O14  1  0.336  0.419  0.141  1.0
  O  O15  1  0.831  0.387  0.636  1.0
  O  O16  1  0.612  0.124  0.747  1.0
  O  O17  1  0.133  0.118  0.753  1.0
  O  O18  1  0.367  0.113  0.500  1.0
  O  O19  1  0.190  0.762  0.858  1.0
  O  O20  1  0.700  0.785  0.863  1.0
  O  O21  1  0.330  0.743  0.629  1.0
  O  O22  1  0.196  0.618  0.365  1.0
  O  O23  1  0.699  0.255  0.367  1.0
  O  O24  1  0.883  0.870  0.250  1.0
  O  O25  1  0.369  0.881  0.254  1.0
[/CIF]
.
The crystal structure described by Sr2GaAlSn2O7 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(11), one O(13), one O(14), one O(3), one O(7), and two equivalent O(12) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(8), one O(9), and two equivalent O(10) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one O(1), one O(12), one O(13), one O(14), one O(2), one O(3), and two equivalent O(11) atoms. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one O(10), one O(5), one O(6), one O(7), one O(8), one O(9), and two equivalent O(4) atoms. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(10), one O(11), one O(2), and one O(7) atom to form corner-sharing GaO4 tetrahedra. In the second Ga site, Ga(2) is bonded to one O(12), one O(2), one O(4), and one O(7) atom to form corner-sharing GaO4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted water-like geometry to one O(1) and one O(3) atom. In the second Al site, Al(2) is bonded in a distorted water-like geometry to one Sn(2), one O(8), and one O(9) atom. There are four inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to one O(10), one O(5), one O(6), one O(8), and one O(9) atom. In the second Sn site, Sn(2) is bonded in a 6-coordinate geometry to one Al(2), one O(1), one O(11), one O(13), one O(14), and one O(3) atom. In the third Sn site, Sn(3) is bonded in a 3-coordinate geometry to one O(4), one O(5), and one O(6) atom. In the fourth Sn site, Sn(4) is bonded in a 3-coordinate geometry to one O(12), one O(13), and one O(14) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(3), one Al(1), and one Sn(2) atom. In the second O site, O(2) is bonded to one Sr(2), one Sr(3), one Ga(1), and one Ga(2) atom to form distorted OSr2Ga2 tetrahedra that share corners with two equivalent O(7)Sr2Ga2 tetrahedra,  a cornercorner with one O(13)Sr2Sn2 trigonal pyramid, and  a cornercorner with one O(6)Sr2Sn2 trigonal pyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(3), one Al(1), and one Sn(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Sr(2), two equivalent Sr(4), one Ga(2), and one Sn(3) atom. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to one Sr(2), one Sr(4), one Sn(1), and one Sn(3) atom. In the sixth O site, O(6) is bonded to one Sr(2), one Sr(4), one Sn(1), and one Sn(3) atom to form distorted corner-sharing OSr2Sn2 trigonal pyramids. In the seventh O site, O(7) is bonded to one Sr(1), one Sr(4), one Ga(1), and one Ga(2) atom to form OSr2Ga2 tetrahedra that share corners with two equivalent O(2)Sr2Ga2 tetrahedra,  a cornercorner with one O(13)Sr2Sn2 trigonal pyramid, and  a cornercorner with one O(6)Sr2Sn2 trigonal pyramid. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), one Sr(4), one Al(2), and one Sn(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Sr(2), one Sr(4), one Al(2), and one Sn(1) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Sr(4), two equivalent Sr(2), one Ga(1), and one Sn(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(3), one Ga(1), and one Sn(2) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Sr(3), two equivalent Sr(1), one Ga(2), and one Sn(4) atom. In the thirteenth O site, O(13) is bonded to one Sr(1), one Sr(3), one Sn(2), and one Sn(4) atom to form distorted corner-sharing OSr2Sn2 trigonal pyramids. In the fourteenth O site, O(14) is bonded in a distorted see-saw-like geometry to one Sr(1), one Sr(3), one Sn(2), and one Sn(4) atom. is represented by the CIF card [CIF]
data_Sr2AlGaSn2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.753
_cell_length_b   6.585
_cell_length_c   12.198
_cell_angle_alpha   105.534
_cell_angle_beta   103.544
_cell_angle_gamma   89.883
_symmetry_Int_Tables_number   1
_cell_volume   431.937
_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  0.152  0.229  0.322  1.0
  Sr  Sr1  1  0.832  0.793  0.675  1.0
  Sr  Sr2  1  0.659  0.621  0.327  1.0
  Sr  Sr3  1  0.329  0.406  0.679  1.0
  Al  Al4  1  0.543  0.296  0.065  1.0
  Al  Al5  1  0.981  0.731  0.938  1.0
  Ga  Ga6  1  0.210  0.847  0.499  1.0
  Ga  Ga7  1  0.700  0.157  0.501  1.0
  Sn  Sn8  1  0.428  0.000  0.849  1.0
  Sn  Sn9  1  0.084  0.653  0.158  1.0
  Sn  Sn10  1  0.901  0.325  0.807  1.0
  Sn  Sn11  1  0.598  0.022  0.194  1.0
  O  O12  1  0.830  0.408  0.144  1.0
  O  O13  1  0.873  0.913  0.501  1.0
  O  O14  1  0.336  0.419  0.141  1.0
  O  O15  1  0.831  0.387  0.636  1.0
  O  O16  1  0.612  0.124  0.747  1.0
  O  O17  1  0.133  0.118  0.753  1.0
  O  O18  1  0.367  0.113  0.500  1.0
  O  O19  1  0.190  0.762  0.858  1.0
  O  O20  1  0.700  0.785  0.863  1.0
  O  O21  1  0.330  0.743  0.629  1.0
  O  O22  1  0.196  0.618  0.365  1.0
  O  O23  1  0.699  0.255  0.367  1.0
  O  O24  1  0.883  0.870  0.250  1.0
  O  O25  1  0.369  0.881  0.254  1.0
[/CIF]
.