The crystal structure described by La3As2O7Br crystallizes in the tetragonal P4_2/mnm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to two equivalent O(2), four equivalent O(3), and two equivalent Br(1) atoms. In the second La site, La(2) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(2), four equivalent O(3), and one Br(1) atom. As(1) is bonded in a distorted T-shaped geometry to one O(2) and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(3) is bonded to one La(1), two equivalent La(2), and one As(1) atom to form distorted OLa3As tetrahedra that share corners with two equivalent O(1)La4 tetrahedra, corners with six equivalent O(3)La3As tetrahedra,  an edgeedge with one O(1)La4 tetrahedra, and edges with two equivalent O(3)La3As tetrahedra. In the second O site, O(1) is bonded to four equivalent La(2) atoms to form OLa4 tetrahedra that share corners with eight equivalent O(3)La3As tetrahedra, edges with two equivalent O(1)La4 tetrahedra, and edges with four equivalent O(3)La3As tetrahedra. In the third O site, O(2) is bonded in a 2-coordinate geometry to one La(1), two equivalent La(2), and one As(1) atom. Br(1) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent La(2) atoms. is represented by the CIF file [CIF]
data_La3As2BrO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.174
_cell_length_b   13.174
_cell_length_c   5.673
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   984.474
_cell_formula_units_Z   4
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
  La  La0  1  0.762  0.238  0.500  1.0
  La  La1  1  0.238  0.762  0.500  1.0
  La  La2  1  0.262  0.262  0.000  1.0
  La  La3  1  0.738  0.738  0.000  1.0
  La  La4  1  0.637  0.953  0.500  1.0
  La  La5  1  0.363  0.047  0.500  1.0
  La  La6  1  0.137  0.547  0.000  1.0
  La  La7  1  0.863  0.453  0.000  1.0
  La  La8  1  0.953  0.637  0.500  1.0
  La  La9  1  0.047  0.363  0.500  1.0
  La  La10  1  0.547  0.137  0.000  1.0
  La  La11  1  0.453  0.863  0.000  1.0
  As  As12  1  0.473  0.289  0.500  1.0
  As  As13  1  0.527  0.711  0.500  1.0
  As  As14  1  0.973  0.211  0.000  1.0
  As  As15  1  0.027  0.789  0.000  1.0
  As  As16  1  0.289  0.473  0.500  1.0
  As  As17  1  0.711  0.527  0.500  1.0
  As  As18  1  0.211  0.973  0.000  1.0
  As  As19  1  0.789  0.027  0.000  1.0
  Br  Br20  1  0.853  0.853  0.500  1.0
  Br  Br21  1  0.147  0.147  0.500  1.0
  Br  Br22  1  0.353  0.647  0.000  1.0
  Br  Br23  1  0.647  0.353  0.000  1.0
  O  O24  1  0.500  0.000  0.250  1.0
  O  O25  1  0.000  0.500  0.750  1.0
  O  O26  1  0.500  0.000  0.750  1.0
  O  O27  1  0.000  0.500  0.250  1.0
  O  O28  1  0.582  0.208  0.500  1.0
  O  O29  1  0.418  0.792  0.500  1.0
  O  O30  1  0.082  0.292  0.000  1.0
  O  O31  1  0.918  0.708  0.000  1.0
  O  O32  1  0.208  0.582  0.500  1.0
  O  O33  1  0.792  0.418  0.500  1.0
  O  O34  1  0.292  0.082  0.000  1.0
  O  O35  1  0.708  0.918  0.000  1.0
  O  O36  1  0.408  0.220  0.263  1.0
  O  O37  1  0.592  0.780  0.263  1.0
  O  O38  1  0.908  0.280  0.763  1.0
  O  O39  1  0.092  0.720  0.763  1.0
  O  O40  1  0.592  0.780  0.737  1.0
  O  O41  1  0.408  0.220  0.737  1.0
  O  O42  1  0.092  0.720  0.237  1.0
  O  O43  1  0.908  0.280  0.237  1.0
  O  O44  1  0.220  0.408  0.263  1.0
  O  O45  1  0.780  0.592  0.263  1.0
  O  O46  1  0.280  0.908  0.763  1.0
  O  O47  1  0.720  0.092  0.763  1.0
  O  O48  1  0.780  0.592  0.737  1.0
  O  O49  1  0.220  0.408  0.737  1.0
  O  O50  1  0.720  0.092  0.237  1.0
  O  O51  1  0.280  0.908  0.237  1.0
[/CIF]
.
The crystal structure described by La3As2O7Br crystallizes in the tetragonal P4_2/mnm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to two equivalent O(2), four equivalent O(3), and two equivalent Br(1) atoms. In the second La site, La(2) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(2), four equivalent O(3), and one Br(1) atom. As(1) is bonded in a distorted T-shaped geometry to one O(2) and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(3) is bonded to one La(1), two equivalent La(2), and one As(1) atom to form distorted OLa3As tetrahedra that share corners with two equivalent O(1)La4 tetrahedra, corners with six equivalent O(3)La3As tetrahedra,  an edgeedge with one O(1)La4 tetrahedra, and edges with two equivalent O(3)La3As tetrahedra. In the second O site, O(1) is bonded to four equivalent La(2) atoms to form OLa4 tetrahedra that share corners with eight equivalent O(3)La3As tetrahedra, edges with two equivalent O(1)La4 tetrahedra, and edges with four equivalent O(3)La3As tetrahedra. In the third O site, O(2) is bonded in a 2-coordinate geometry to one La(1), two equivalent La(2), and one As(1) atom. Br(1) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent La(2) atoms. is represented by the CIF file [CIF]
data_La3As2BrO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.174
_cell_length_b   13.174
_cell_length_c   5.673
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   984.474
_cell_formula_units_Z   4
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
  La  La0  1  0.762  0.238  0.500  1.0
  La  La1  1  0.238  0.762  0.500  1.0
  La  La2  1  0.262  0.262  0.000  1.0
  La  La3  1  0.738  0.738  0.000  1.0
  La  La4  1  0.637  0.953  0.500  1.0
  La  La5  1  0.363  0.047  0.500  1.0
  La  La6  1  0.137  0.547  0.000  1.0
  La  La7  1  0.863  0.453  0.000  1.0
  La  La8  1  0.953  0.637  0.500  1.0
  La  La9  1  0.047  0.363  0.500  1.0
  La  La10  1  0.547  0.137  0.000  1.0
  La  La11  1  0.453  0.863  0.000  1.0
  As  As12  1  0.473  0.289  0.500  1.0
  As  As13  1  0.527  0.711  0.500  1.0
  As  As14  1  0.973  0.211  0.000  1.0
  As  As15  1  0.027  0.789  0.000  1.0
  As  As16  1  0.289  0.473  0.500  1.0
  As  As17  1  0.711  0.527  0.500  1.0
  As  As18  1  0.211  0.973  0.000  1.0
  As  As19  1  0.789  0.027  0.000  1.0
  Br  Br20  1  0.853  0.853  0.500  1.0
  Br  Br21  1  0.147  0.147  0.500  1.0
  Br  Br22  1  0.353  0.647  0.000  1.0
  Br  Br23  1  0.647  0.353  0.000  1.0
  O  O24  1  0.500  0.000  0.250  1.0
  O  O25  1  0.000  0.500  0.750  1.0
  O  O26  1  0.500  0.000  0.750  1.0
  O  O27  1  0.000  0.500  0.250  1.0
  O  O28  1  0.582  0.208  0.500  1.0
  O  O29  1  0.418  0.792  0.500  1.0
  O  O30  1  0.082  0.292  0.000  1.0
  O  O31  1  0.918  0.708  0.000  1.0
  O  O32  1  0.208  0.582  0.500  1.0
  O  O33  1  0.792  0.418  0.500  1.0
  O  O34  1  0.292  0.082  0.000  1.0
  O  O35  1  0.708  0.918  0.000  1.0
  O  O36  1  0.408  0.220  0.263  1.0
  O  O37  1  0.592  0.780  0.263  1.0
  O  O38  1  0.908  0.280  0.763  1.0
  O  O39  1  0.092  0.720  0.763  1.0
  O  O40  1  0.592  0.780  0.737  1.0
  O  O41  1  0.408  0.220  0.737  1.0
  O  O42  1  0.092  0.720  0.237  1.0
  O  O43  1  0.908  0.280  0.237  1.0
  O  O44  1  0.220  0.408  0.263  1.0
  O  O45  1  0.780  0.592  0.263  1.0
  O  O46  1  0.280  0.908  0.763  1.0
  O  O47  1  0.720  0.092  0.763  1.0
  O  O48  1  0.780  0.592  0.737  1.0
  O  O49  1  0.220  0.408  0.737  1.0
  O  O50  1  0.720  0.092  0.237  1.0
  O  O51  1  0.280  0.908  0.237  1.0
[/CIF]
.