The crystal structure described by SrSmAl3O7 crystallizes in the orthorhombic Cmm2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Sm(1) is bonded in a 8-coordinate geometry to one O(2), one O(6), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(1), one O(6), and two equivalent O(3) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to one O(2), one O(5), and two equivalent O(4) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Al(3) atoms. In the second O site, O(6) is bonded to two equivalent Sm(1) and two equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OSm2Al2 tetrahedra. In the third O site, O(1) is bonded to one Sr(1), two equivalent Sm(1), and one Al(2) atom to form distorted OSrSm2Al tetrahedra that share  a cornercorner with one O(6)Sm2Al2 tetrahedra,  an edgeedge with one O(6)Sm2Al2 tetrahedra, and  an edgeedge with one O(1)SrSm2Al tetrahedra. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Sm(1), and one Al(3) atom. In the fifth O site, O(3) is bonded in a 2-coordinate geometry to one Sr(1), one Sm(1), one Al(1), and one Al(2) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Sm(1), one Al(1), and one Al(3) atom. is represented by the CIF file [CIF]
data_SrSmAl3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.892
_cell_length_b   7.892
_cell_length_c   5.214
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.596
_symmetry_Int_Tables_number   1
_cell_volume   324.722
_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  0.162  0.838  0.490  1.0
  Sr  Sr1  1  0.838  0.162  0.490  1.0
  Sm  Sm2  1  0.662  0.662  0.515  1.0
  Sm  Sm3  1  0.338  0.338  0.515  1.0
  Al  Al4  1  0.500  0.000  0.996  1.0
  Al  Al5  1  0.000  0.500  0.996  1.0
  Al  Al6  1  0.360  0.640  0.041  1.0
  Al  Al7  1  0.853  0.853  0.961  1.0
  Al  Al8  1  0.640  0.360  0.041  1.0
  Al  Al9  1  0.147  0.147  0.961  1.0
  O  O10  1  0.372  0.628  0.705  1.0
  O  O11  1  0.844  0.844  0.294  1.0
  O  O12  1  0.628  0.372  0.705  1.0
  O  O13  1  0.156  0.156  0.294  1.0
  O  O14  1  0.419  0.834  0.189  1.0
  O  O15  1  0.905  0.659  0.801  1.0
  O  O16  1  0.581  0.166  0.189  1.0
  O  O17  1  0.095  0.341  0.801  1.0
  O  O18  1  0.341  0.095  0.801  1.0
  O  O19  1  0.834  0.419  0.189  1.0
  O  O20  1  0.659  0.905  0.801  1.0
  O  O21  1  0.166  0.581  0.189  1.0
  O  O22  1  0.000  0.000  0.839  1.0
  O  O23  1  0.500  0.500  0.200  1.0
[/CIF]
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The crystal structure described by SrSmAl3O7 crystallizes in the orthorhombic Cmm2 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Sm(1) is bonded in a 8-coordinate geometry to one O(2), one O(6), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(1), one O(6), and two equivalent O(3) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to one O(2), one O(5), and two equivalent O(4) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Al(3) atoms. In the second O site, O(6) is bonded to two equivalent Sm(1) and two equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OSm2Al2 tetrahedra. In the third O site, O(1) is bonded to one Sr(1), two equivalent Sm(1), and one Al(2) atom to form distorted OSrSm2Al tetrahedra that share  a cornercorner with one O(6)Sm2Al2 tetrahedra,  an edgeedge with one O(6)Sm2Al2 tetrahedra, and  an edgeedge with one O(1)SrSm2Al tetrahedra. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Sm(1), and one Al(3) atom. In the fifth O site, O(3) is bonded in a 2-coordinate geometry to one Sr(1), one Sm(1), one Al(1), and one Al(2) atom. In the sixth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Sm(1), one Al(1), and one Al(3) atom. is represented by the CIF file [CIF]
data_SrSmAl3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.892
_cell_length_b   7.892
_cell_length_c   5.214
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.596
_symmetry_Int_Tables_number   1
_cell_volume   324.722
_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  0.162  0.838  0.490  1.0
  Sr  Sr1  1  0.838  0.162  0.490  1.0
  Sm  Sm2  1  0.662  0.662  0.515  1.0
  Sm  Sm3  1  0.338  0.338  0.515  1.0
  Al  Al4  1  0.500  0.000  0.996  1.0
  Al  Al5  1  0.000  0.500  0.996  1.0
  Al  Al6  1  0.360  0.640  0.041  1.0
  Al  Al7  1  0.853  0.853  0.961  1.0
  Al  Al8  1  0.640  0.360  0.041  1.0
  Al  Al9  1  0.147  0.147  0.961  1.0
  O  O10  1  0.372  0.628  0.705  1.0
  O  O11  1  0.844  0.844  0.294  1.0
  O  O12  1  0.628  0.372  0.705  1.0
  O  O13  1  0.156  0.156  0.294  1.0
  O  O14  1  0.419  0.834  0.189  1.0
  O  O15  1  0.905  0.659  0.801  1.0
  O  O16  1  0.581  0.166  0.189  1.0
  O  O17  1  0.095  0.341  0.801  1.0
  O  O18  1  0.341  0.095  0.801  1.0
  O  O19  1  0.834  0.419  0.189  1.0
  O  O20  1  0.659  0.905  0.801  1.0
  O  O21  1  0.166  0.581  0.189  1.0
  O  O22  1  0.000  0.000  0.839  1.0
  O  O23  1  0.500  0.500  0.200  1.0
[/CIF]
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