The crystal structure described by Sr2Cu3AlO7 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(7), two equivalent O(11), and two equivalent O(13) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(8), two equivalent O(12), and two equivalent O(14) atoms. In the third Sr site, Sr(3) is bonded in a 7-coordinate geometry to one O(2), one O(5), one O(9), two equivalent O(11), and two equivalent O(13) atoms. In the fourth Sr site, Sr(4) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(6), two equivalent O(12), and two equivalent O(14) atoms. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a see-saw-like geometry to one O(1), one O(11), one O(14), and one O(2) atom. In the second Cu site, Cu(2) is bonded in a see-saw-like geometry to one O(1), one O(12), one O(13), and one O(2) atom. In the third Cu site, Cu(3) is bonded to one O(13), one O(3), one O(5), one O(7), and one O(9) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(5)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one O(10), one O(14), one O(4), one O(6), and one O(8) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(6)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. In the fifth Cu site, Cu(5) is bonded to one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(3)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. In the sixth Cu site, Cu(6) is bonded to one O(10), one O(12), one O(4), one O(6), and one O(8) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(4)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(10), one O(5), one O(6), and one O(9) atom to form distorted AlO4 tetrahedra that share corners with two equivalent Cu(3)O5 square pyramids, corners with two equivalent Cu(4)O5 square pyramids, corners with two equivalent Cu(5)O5 square pyramids, and corners with two equivalent Cu(6)O5 square pyramids. In the second Al site, Al(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form distorted AlO4 tetrahedra that share corners with two equivalent Cu(3)O5 square pyramids, corners with two equivalent Cu(4)O5 square pyramids, corners with two equivalent Cu(5)O5 square pyramids, and corners with two equivalent Cu(6)O5 square pyramids. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Sr(4), one Cu(1), and one Cu(2) atom to form distorted OSr2Cu2 tetrahedra that share  a cornercorner with one O(11)Sr4Cu2 octahedra,  a cornercorner with one O(12)Sr4Cu2 octahedra,  a cornercorner with one O(13)Sr4Cu2 octahedra,  a cornercorner with one O(14)Sr4Cu2 octahedra, corners with two equivalent O(2)Sr2Cu2 tetrahedra,  an edgeedge with one O(11)Sr4Cu2 octahedra,  an edgeedge with one O(12)Sr4Cu2 octahedra,  an edgeedge with one O(13)Sr4Cu2 octahedra, and  an edgeedge with one O(14)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 81-85°. In the second O site, O(2) is bonded to one Sr(2), one Sr(3), one Cu(1), and one Cu(2) atom to form distorted OSr2Cu2 tetrahedra that share  a cornercorner with one O(11)Sr4Cu2 octahedra,  a cornercorner with one O(12)Sr4Cu2 octahedra,  a cornercorner with one O(13)Sr4Cu2 octahedra,  a cornercorner with one O(14)Sr4Cu2 octahedra, corners with two equivalent O(1)Sr2Cu2 tetrahedra,  an edgeedge with one O(11)Sr4Cu2 octahedra,  an edgeedge with one O(12)Sr4Cu2 octahedra,  an edgeedge with one O(13)Sr4Cu2 octahedra, and  an edgeedge with one O(14)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 81-85°. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(3), one Cu(5), and one Al(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(4), one Cu(6), and one Al(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(3), one Cu(3), one Cu(5), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(4), one Cu(4), one Cu(6), and one Al(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(3), one Cu(5), and one Al(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(4), one Cu(6), and one Al(2) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Sr(3), one Cu(3), one Cu(5), and one Al(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Sr(4), one Cu(4), one Cu(6), and one Al(1) atom. In the eleventh O site, O(11) is bonded to two equivalent Sr(1), two equivalent Sr(3), one Cu(1), and one Cu(5) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(14)Sr4Cu2 octahedra, corners with four equivalent O(11)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(13)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the twelfth O site, O(12) is bonded to two equivalent Sr(2), two equivalent Sr(4), one Cu(2), and one Cu(6) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(13)Sr4Cu2 octahedra, corners with four equivalent O(12)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(14)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the thirteenth O site, O(13) is bonded to two equivalent Sr(1), two equivalent Sr(3), one Cu(2), and one Cu(3) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(12)Sr4Cu2 octahedra, corners with four equivalent O(13)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(11)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the fourteenth O site, O(14) is bonded to two equivalent Sr(2), two equivalent Sr(4), one Cu(1), and one Cu(4) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(11)Sr4Cu2 octahedra, corners with four equivalent O(14)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(12)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. is represented by the CIF card [CIF]
data_Sr2AlCu3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.357
_cell_length_b   5.309
_cell_length_c   12.059
_cell_angle_alpha   102.699
_cell_angle_beta   102.812
_cell_angle_gamma   90.085
_symmetry_Int_Tables_number   1
_cell_volume   325.800
_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  0.335  0.347  0.698  1.0
  Sr  Sr1  1  0.640  0.657  0.302  1.0
  Sr  Sr2  1  0.835  0.854  0.698  1.0
  Sr  Sr3  1  0.140  0.151  0.302  1.0
  Al  Al4  1  0.986  0.002  0.000  1.0
  Al  Al5  1  0.483  0.496  0.000  1.0
  Cu  Cu6  1  0.259  0.698  0.500  1.0
  Cu  Cu7  1  0.759  0.305  0.500  1.0
  Cu  Cu8  1  0.922  0.440  0.880  1.0
  Cu  Cu9  1  0.046  0.563  0.121  1.0
  Cu  Cu10  1  0.422  0.938  0.879  1.0
  Cu  Cu11  1  0.548  0.061  0.121  1.0
  O  O12  1  0.102  0.360  0.500  1.0
  O  O13  1  0.602  0.641  0.500  1.0
  O  O14  1  0.249  0.266  0.890  1.0
  O  O15  1  0.364  0.733  0.110  1.0
  O  O16  1  0.750  0.123  0.891  1.0
  O  O17  1  0.866  0.881  0.111  1.0
  O  O18  1  0.606  0.622  0.892  1.0
  O  O19  1  0.719  0.379  0.110  1.0
  O  O20  1  0.105  0.769  0.891  1.0
  O  O21  1  0.220  0.235  0.109  1.0
  O  O22  1  0.312  0.834  0.662  1.0
  O  O23  1  0.652  0.168  0.338  1.0
  O  O24  1  0.811  0.329  0.661  1.0
  O  O25  1  0.152  0.674  0.339  1.0
[/CIF]
.
The crystal structure described by Sr2Cu3AlO7 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(7), two equivalent O(11), and two equivalent O(13) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(8), two equivalent O(12), and two equivalent O(14) atoms. In the third Sr site, Sr(3) is bonded in a 7-coordinate geometry to one O(2), one O(5), one O(9), two equivalent O(11), and two equivalent O(13) atoms. In the fourth Sr site, Sr(4) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(6), two equivalent O(12), and two equivalent O(14) atoms. There are six inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a see-saw-like geometry to one O(1), one O(11), one O(14), and one O(2) atom. In the second Cu site, Cu(2) is bonded in a see-saw-like geometry to one O(1), one O(12), one O(13), and one O(2) atom. In the third Cu site, Cu(3) is bonded to one O(13), one O(3), one O(5), one O(7), and one O(9) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(5)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one O(10), one O(14), one O(4), one O(6), and one O(8) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(6)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. In the fifth Cu site, Cu(5) is bonded to one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(3)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. In the sixth Cu site, Cu(6) is bonded to one O(10), one O(12), one O(4), one O(6), and one O(8) atom to form distorted CuO5 square pyramids that share corners with four equivalent Cu(4)O5 square pyramids, corners with two equivalent Al(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(10), one O(5), one O(6), and one O(9) atom to form distorted AlO4 tetrahedra that share corners with two equivalent Cu(3)O5 square pyramids, corners with two equivalent Cu(4)O5 square pyramids, corners with two equivalent Cu(5)O5 square pyramids, and corners with two equivalent Cu(6)O5 square pyramids. In the second Al site, Al(2) is bonded to one O(3), one O(4), one O(7), and one O(8) atom to form distorted AlO4 tetrahedra that share corners with two equivalent Cu(3)O5 square pyramids, corners with two equivalent Cu(4)O5 square pyramids, corners with two equivalent Cu(5)O5 square pyramids, and corners with two equivalent Cu(6)O5 square pyramids. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), one Sr(4), one Cu(1), and one Cu(2) atom to form distorted OSr2Cu2 tetrahedra that share  a cornercorner with one O(11)Sr4Cu2 octahedra,  a cornercorner with one O(12)Sr4Cu2 octahedra,  a cornercorner with one O(13)Sr4Cu2 octahedra,  a cornercorner with one O(14)Sr4Cu2 octahedra, corners with two equivalent O(2)Sr2Cu2 tetrahedra,  an edgeedge with one O(11)Sr4Cu2 octahedra,  an edgeedge with one O(12)Sr4Cu2 octahedra,  an edgeedge with one O(13)Sr4Cu2 octahedra, and  an edgeedge with one O(14)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 81-85°. In the second O site, O(2) is bonded to one Sr(2), one Sr(3), one Cu(1), and one Cu(2) atom to form distorted OSr2Cu2 tetrahedra that share  a cornercorner with one O(11)Sr4Cu2 octahedra,  a cornercorner with one O(12)Sr4Cu2 octahedra,  a cornercorner with one O(13)Sr4Cu2 octahedra,  a cornercorner with one O(14)Sr4Cu2 octahedra, corners with two equivalent O(1)Sr2Cu2 tetrahedra,  an edgeedge with one O(11)Sr4Cu2 octahedra,  an edgeedge with one O(12)Sr4Cu2 octahedra,  an edgeedge with one O(13)Sr4Cu2 octahedra, and  an edgeedge with one O(14)Sr4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 81-85°. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(3), one Cu(5), and one Al(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(4), one Cu(6), and one Al(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Sr(3), one Cu(3), one Cu(5), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sr(4), one Cu(4), one Cu(6), and one Al(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Cu(3), one Cu(5), and one Al(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(2), one Cu(4), one Cu(6), and one Al(2) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Sr(3), one Cu(3), one Cu(5), and one Al(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Sr(4), one Cu(4), one Cu(6), and one Al(1) atom. In the eleventh O site, O(11) is bonded to two equivalent Sr(1), two equivalent Sr(3), one Cu(1), and one Cu(5) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(14)Sr4Cu2 octahedra, corners with four equivalent O(11)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(13)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the twelfth O site, O(12) is bonded to two equivalent Sr(2), two equivalent Sr(4), one Cu(2), and one Cu(6) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(13)Sr4Cu2 octahedra, corners with four equivalent O(12)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(14)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the thirteenth O site, O(13) is bonded to two equivalent Sr(1), two equivalent Sr(3), one Cu(2), and one Cu(3) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(12)Sr4Cu2 octahedra, corners with four equivalent O(13)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(11)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the fourteenth O site, O(14) is bonded to two equivalent Sr(2), two equivalent Sr(4), one Cu(1), and one Cu(4) atom to form distorted OSr4Cu2 octahedra that share  a cornercorner with one O(11)Sr4Cu2 octahedra, corners with four equivalent O(14)Sr4Cu2 octahedra,  a cornercorner with one O(1)Sr2Cu2 tetrahedra,  a cornercorner with one O(2)Sr2Cu2 tetrahedra, edges with four equivalent O(12)Sr4Cu2 octahedra,  an edgeedge with one O(1)Sr2Cu2 tetrahedra, and  an edgeedge with one O(2)Sr2Cu2 tetrahedra. The corner-sharing octahedral tilt angles range from 18-20°. is represented by the CIF card [CIF]
data_Sr2AlCu3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.357
_cell_length_b   5.309
_cell_length_c   12.059
_cell_angle_alpha   102.699
_cell_angle_beta   102.812
_cell_angle_gamma   90.085
_symmetry_Int_Tables_number   1
_cell_volume   325.800
_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  0.335  0.347  0.698  1.0
  Sr  Sr1  1  0.640  0.657  0.302  1.0
  Sr  Sr2  1  0.835  0.854  0.698  1.0
  Sr  Sr3  1  0.140  0.151  0.302  1.0
  Al  Al4  1  0.986  0.002  0.000  1.0
  Al  Al5  1  0.483  0.496  0.000  1.0
  Cu  Cu6  1  0.259  0.698  0.500  1.0
  Cu  Cu7  1  0.759  0.305  0.500  1.0
  Cu  Cu8  1  0.922  0.440  0.880  1.0
  Cu  Cu9  1  0.046  0.563  0.121  1.0
  Cu  Cu10  1  0.422  0.938  0.879  1.0
  Cu  Cu11  1  0.548  0.061  0.121  1.0
  O  O12  1  0.102  0.360  0.500  1.0
  O  O13  1  0.602  0.641  0.500  1.0
  O  O14  1  0.249  0.266  0.890  1.0
  O  O15  1  0.364  0.733  0.110  1.0
  O  O16  1  0.750  0.123  0.891  1.0
  O  O17  1  0.866  0.881  0.111  1.0
  O  O18  1  0.606  0.622  0.892  1.0
  O  O19  1  0.719  0.379  0.110  1.0
  O  O20  1  0.105  0.769  0.891  1.0
  O  O21  1  0.220  0.235  0.109  1.0
  O  O22  1  0.312  0.834  0.662  1.0
  O  O23  1  0.652  0.168  0.338  1.0
  O  O24  1  0.811  0.329  0.661  1.0
  O  O25  1  0.152  0.674  0.339  1.0
[/CIF]
.