The material described by CaPrAl3O7 crystallizes in the orthorhombic Cmm2 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Pr(1) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(4), and two equivalent O(5) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(2), one O(3), and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Pr(1), and one Al(1) atom to form distorted OCaPr2Al tetrahedra that share  a cornercorner with one O(3)Ca2Al2 tetrahedra,  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(2)Ca2PrAl tetrahedra,  an edgeedge with one O(1)CaPr2Al tetrahedra, and  an edgeedge with one O(4)Pr2Al2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1), one Pr(1), and one Al(2) atom to form distorted OCa2PrAl tetrahedra that share  a cornercorner with one O(3)Ca2Al2 tetrahedra,  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(1)CaPr2Al tetrahedra,  an edgeedge with one O(3)Ca2Al2 tetrahedra, and  an edgeedge with one O(2)Ca2PrAl tetrahedra. In the third O site, O(3) is bonded to two equivalent Ca(1) and two equivalent Al(2) atoms to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(2)Ca2PrAl tetrahedra, corners with two equivalent O(1)CaPr2Al tetrahedra, and edges with two equivalent O(2)Ca2PrAl tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Pr(1) and two equivalent Al(1) atoms to form distorted OPr2Al2 tetrahedra that share corners with two equivalent O(2)Ca2PrAl tetrahedra, corners with two equivalent O(1)CaPr2Al tetrahedra, and edges with two equivalent O(1)CaPr2Al tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Pr(1), one Al(1), and one Al(3) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Pr(1), one Al(2), and one Al(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaPrAl3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.836
_cell_length_b   7.836
_cell_length_c   5.184
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   91.080
_symmetry_Int_Tables_number   1
_cell_volume   318.250
_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
  Ca  Ca0  1  0.660  0.660  0.483  1.0
  Ca  Ca1  1  0.340  0.340  0.483  1.0
  Pr  Pr2  1  0.836  0.164  0.509  1.0
  Pr  Pr3  1  0.164  0.836  0.509  1.0
  Al  Al4  1  0.854  0.854  0.040  1.0
  Al  Al5  1  0.641  0.359  0.958  1.0
  Al  Al6  1  0.146  0.146  0.040  1.0
  Al  Al7  1  0.359  0.641  0.958  1.0
  Al  Al8  1  0.500  0.000  0.006  1.0
  Al  Al9  1  0.000  0.500  0.006  1.0
  O  O10  1  0.862  0.862  0.702  1.0
  O  O11  1  0.644  0.356  0.294  1.0
  O  O12  1  0.138  0.138  0.702  1.0
  O  O13  1  0.356  0.644  0.294  1.0
  O  O14  1  0.500  0.500  0.810  1.0
  O  O15  1  0.000  0.000  0.186  1.0
  O  O16  1  0.664  0.914  0.199  1.0
  O  O17  1  0.840  0.408  0.806  1.0
  O  O18  1  0.336  0.086  0.199  1.0
  O  O19  1  0.160  0.592  0.806  1.0
  O  O20  1  0.408  0.840  0.806  1.0
  O  O21  1  0.086  0.336  0.199  1.0
  O  O22  1  0.592  0.160  0.806  1.0
  O  O23  1  0.914  0.664  0.199  1.0
[/CIF]
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The material described by CaPrAl3O7 crystallizes in the orthorhombic Cmm2 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Pr(1) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(4), and two equivalent O(5) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(2), one O(3), and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to two equivalent O(5) and two equivalent O(6) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Pr(1), and one Al(1) atom to form distorted OCaPr2Al tetrahedra that share  a cornercorner with one O(3)Ca2Al2 tetrahedra,  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(2)Ca2PrAl tetrahedra,  an edgeedge with one O(1)CaPr2Al tetrahedra, and  an edgeedge with one O(4)Pr2Al2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1), one Pr(1), and one Al(2) atom to form distorted OCa2PrAl tetrahedra that share  a cornercorner with one O(3)Ca2Al2 tetrahedra,  a cornercorner with one O(4)Pr2Al2 tetrahedra, corners with four equivalent O(1)CaPr2Al tetrahedra,  an edgeedge with one O(3)Ca2Al2 tetrahedra, and  an edgeedge with one O(2)Ca2PrAl tetrahedra. In the third O site, O(3) is bonded to two equivalent Ca(1) and two equivalent Al(2) atoms to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(2)Ca2PrAl tetrahedra, corners with two equivalent O(1)CaPr2Al tetrahedra, and edges with two equivalent O(2)Ca2PrAl tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Pr(1) and two equivalent Al(1) atoms to form distorted OPr2Al2 tetrahedra that share corners with two equivalent O(2)Ca2PrAl tetrahedra, corners with two equivalent O(1)CaPr2Al tetrahedra, and edges with two equivalent O(1)CaPr2Al tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Ca(1), one Pr(1), one Al(1), and one Al(3) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Pr(1), one Al(2), and one Al(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaPrAl3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.836
_cell_length_b   7.836
_cell_length_c   5.184
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   91.080
_symmetry_Int_Tables_number   1
_cell_volume   318.250
_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
  Ca  Ca0  1  0.660  0.660  0.483  1.0
  Ca  Ca1  1  0.340  0.340  0.483  1.0
  Pr  Pr2  1  0.836  0.164  0.509  1.0
  Pr  Pr3  1  0.164  0.836  0.509  1.0
  Al  Al4  1  0.854  0.854  0.040  1.0
  Al  Al5  1  0.641  0.359  0.958  1.0
  Al  Al6  1  0.146  0.146  0.040  1.0
  Al  Al7  1  0.359  0.641  0.958  1.0
  Al  Al8  1  0.500  0.000  0.006  1.0
  Al  Al9  1  0.000  0.500  0.006  1.0
  O  O10  1  0.862  0.862  0.702  1.0
  O  O11  1  0.644  0.356  0.294  1.0
  O  O12  1  0.138  0.138  0.702  1.0
  O  O13  1  0.356  0.644  0.294  1.0
  O  O14  1  0.500  0.500  0.810  1.0
  O  O15  1  0.000  0.000  0.186  1.0
  O  O16  1  0.664  0.914  0.199  1.0
  O  O17  1  0.840  0.408  0.806  1.0
  O  O18  1  0.336  0.086  0.199  1.0
  O  O19  1  0.160  0.592  0.806  1.0
  O  O20  1  0.408  0.840  0.806  1.0
  O  O21  1  0.086  0.336  0.199  1.0
  O  O22  1  0.592  0.160  0.806  1.0
  O  O23  1  0.914  0.664  0.199  1.0
[/CIF]
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