The structure described by Sr2YNi2AlO7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and three equivalent O(4) atoms. Y(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. Ni(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NiO5 trigonal bipyramids that share  a cornercorner with one Al(1)O4 tetrahedra and corners with four equivalent Ni(1)O5 trigonal bipyramids. Al(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form AlO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Ni(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to three equivalent Sr(1), one Ni(1), and one Al(1) atom. In the second O site, O(1) is bonded to two equivalent Sr(1) and two equivalent Al(1) atoms to form distorted OSr2Al2 tetrahedra that share corners with four equivalent O(2)Sr2Y2Ni2 octahedra, corners with four equivalent O(3)Sr2Y2Ni2 octahedra, and corners with two equivalent O(1)Sr2Al2 tetrahedra. The corner-sharing octahedral tilt angles range from 15-81°. In the third O site, O(2) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ni(1) atoms to form distorted OSr2Y2Ni2 octahedra that share corners with four equivalent O(2)Sr2Y2Ni2 octahedra, corners with four equivalent O(3)Sr2Y2Ni2 octahedra, corners with two equivalent O(1)Sr2Al2 tetrahedra, edges with three equivalent O(3)Sr2Y2Ni2 octahedra, faces with two equivalent O(2)Sr2Y2Ni2 octahedra, and faces with two equivalent O(3)Sr2Y2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 2-71°. In the fourth O site, O(3) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ni(1) atoms to form distorted OSr2Y2Ni2 octahedra that share corners with four equivalent O(2)Sr2Y2Ni2 octahedra, corners with four equivalent O(3)Sr2Y2Ni2 octahedra, corners with two equivalent O(1)Sr2Al2 tetrahedra, edges with three equivalent O(2)Sr2Y2Ni2 octahedra, faces with two equivalent O(2)Sr2Y2Ni2 octahedra, and faces with two equivalent O(3)Sr2Y2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 2-71°. is represented by the CIF card [CIF]
data_Sr2YAlNi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.669
_cell_length_b   11.669
_cell_length_c   11.669
_cell_angle_alpha   152.622
_cell_angle_beta   151.979
_cell_angle_gamma   39.577
_symmetry_Int_Tables_number   1
_cell_volume   342.634
_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  0.831  0.833  0.964  1.0
  Sr  Sr1  1  0.169  0.134  0.002  1.0
  Sr  Sr2  1  0.631  0.634  0.964  1.0
  Sr  Sr3  1  0.369  0.333  0.002  1.0
  Y  Y4  1  0.500  0.483  0.983  1.0
  Y  Y5  1  0.000  0.983  0.983  1.0
  Al  Al6  1  0.171  0.761  0.432  1.0
  Al  Al7  1  0.829  0.261  0.591  1.0
  Ni  Ni8  1  0.917  0.396  0.481  1.0
  Ni  Ni9  1  0.083  0.564  0.479  1.0
  Ni  Ni10  1  0.585  0.064  0.481  1.0
  Ni  Ni11  1  0.415  0.896  0.479  1.0
  O  O12  1  0.907  0.578  0.985  1.0
  O  O13  1  0.093  0.078  0.671  1.0
  O  O14  1  0.696  0.675  0.499  1.0
  O  O15  1  0.304  0.803  0.979  1.0
  O  O16  1  0.324  0.303  0.499  1.0
  O  O17  1  0.676  0.175  0.979  1.0
  O  O18  1  0.173  0.153  0.463  1.0
  O  O19  1  0.827  0.290  0.979  1.0
  O  O20  1  0.811  0.790  0.463  1.0
  O  O21  1  0.189  0.653  0.979  1.0
  O  O22  1  0.375  0.777  0.509  1.0
  O  O23  1  0.625  0.134  0.402  1.0
  O  O24  1  0.232  0.634  0.509  1.0
  O  O25  1  0.768  0.277  0.402  1.0
[/CIF]
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The structure described by Sr2YNi2AlO7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and three equivalent O(4) atoms. Y(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. Ni(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NiO5 trigonal bipyramids that share  a cornercorner with one Al(1)O4 tetrahedra and corners with four equivalent Ni(1)O5 trigonal bipyramids. Al(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form AlO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Ni(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to three equivalent Sr(1), one Ni(1), and one Al(1) atom. In the second O site, O(1) is bonded to two equivalent Sr(1) and two equivalent Al(1) atoms to form distorted OSr2Al2 tetrahedra that share corners with four equivalent O(2)Sr2Y2Ni2 octahedra, corners with four equivalent O(3)Sr2Y2Ni2 octahedra, and corners with two equivalent O(1)Sr2Al2 tetrahedra. The corner-sharing octahedral tilt angles range from 15-81°. In the third O site, O(2) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ni(1) atoms to form distorted OSr2Y2Ni2 octahedra that share corners with four equivalent O(2)Sr2Y2Ni2 octahedra, corners with four equivalent O(3)Sr2Y2Ni2 octahedra, corners with two equivalent O(1)Sr2Al2 tetrahedra, edges with three equivalent O(3)Sr2Y2Ni2 octahedra, faces with two equivalent O(2)Sr2Y2Ni2 octahedra, and faces with two equivalent O(3)Sr2Y2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 2-71°. In the fourth O site, O(3) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ni(1) atoms to form distorted OSr2Y2Ni2 octahedra that share corners with four equivalent O(2)Sr2Y2Ni2 octahedra, corners with four equivalent O(3)Sr2Y2Ni2 octahedra, corners with two equivalent O(1)Sr2Al2 tetrahedra, edges with three equivalent O(2)Sr2Y2Ni2 octahedra, faces with two equivalent O(2)Sr2Y2Ni2 octahedra, and faces with two equivalent O(3)Sr2Y2Ni2 octahedra. The corner-sharing octahedral tilt angles range from 2-71°. is represented by the CIF card [CIF]
data_Sr2YAlNi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.669
_cell_length_b   11.669
_cell_length_c   11.669
_cell_angle_alpha   152.622
_cell_angle_beta   151.979
_cell_angle_gamma   39.577
_symmetry_Int_Tables_number   1
_cell_volume   342.634
_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  0.831  0.833  0.964  1.0
  Sr  Sr1  1  0.169  0.134  0.002  1.0
  Sr  Sr2  1  0.631  0.634  0.964  1.0
  Sr  Sr3  1  0.369  0.333  0.002  1.0
  Y  Y4  1  0.500  0.483  0.983  1.0
  Y  Y5  1  0.000  0.983  0.983  1.0
  Al  Al6  1  0.171  0.761  0.432  1.0
  Al  Al7  1  0.829  0.261  0.591  1.0
  Ni  Ni8  1  0.917  0.396  0.481  1.0
  Ni  Ni9  1  0.083  0.564  0.479  1.0
  Ni  Ni10  1  0.585  0.064  0.481  1.0
  Ni  Ni11  1  0.415  0.896  0.479  1.0
  O  O12  1  0.907  0.578  0.985  1.0
  O  O13  1  0.093  0.078  0.671  1.0
  O  O14  1  0.696  0.675  0.499  1.0
  O  O15  1  0.304  0.803  0.979  1.0
  O  O16  1  0.324  0.303  0.499  1.0
  O  O17  1  0.676  0.175  0.979  1.0
  O  O18  1  0.173  0.153  0.463  1.0
  O  O19  1  0.827  0.290  0.979  1.0
  O  O20  1  0.811  0.790  0.463  1.0
  O  O21  1  0.189  0.653  0.979  1.0
  O  O22  1  0.375  0.777  0.509  1.0
  O  O23  1  0.625  0.134  0.402  1.0
  O  O24  1  0.232  0.634  0.509  1.0
  O  O25  1  0.768  0.277  0.402  1.0
[/CIF]
.