The crystal structure described by Sr3LaBr9 crystallizes in the monoclinic Pc space group. There are six inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one Br(1), one Br(10), one Br(13), one Br(14), one Br(4), one Br(5), and one Br(9) atom to form distorted SrBr7 pentagonal bipyramids that share corners with two equivalent Sr(6)Br7 pentagonal bipyramids, corners with two equivalent La(2)Br7 pentagonal bipyramids,  an edgeedge with one Sr(3)Br7 pentagonal bipyramid, and edges with two equivalent Sr(6)Br7 pentagonal bipyramids. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one Br(11), one Br(12), one Br(15), one Br(2), one Br(3), one Br(6), one Br(7), and one Br(8) atom. In the third Sr site, Sr(3) is bonded to one Br(12), one Br(13), one Br(17), one Br(18), one Br(3), one Br(8), and one Br(9) atom to form distorted SrBr7 pentagonal bipyramids that share corners with two equivalent Sr(6)Br7 pentagonal bipyramids, corners with two equivalent La(2)Br7 pentagonal bipyramids,  an edgeedge with one Sr(1)Br7 pentagonal bipyramid, and edges with two equivalent La(2)Br7 pentagonal bipyramids. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(11), one Br(14), one Br(15), one Br(16), one Br(2), and one Br(7) atom. In the fifth Sr site, Sr(5) is bonded in a 8-coordinate geometry to one Br(11), one Br(12), one Br(15), one Br(16), one Br(17), one Br(2), one Br(3), and one Br(6) atom. In the sixth Sr site, Sr(6) is bonded to one Br(1), one Br(10), one Br(13), one Br(14), one Br(18), one Br(4), and one Br(5) atom to form distorted SrBr7 pentagonal bipyramids that share corners with two equivalent Sr(1)Br7 pentagonal bipyramids, corners with two equivalent Sr(3)Br7 pentagonal bipyramids,  an edgeedge with one La(2)Br7 pentagonal bipyramid, and edges with two equivalent Sr(1)Br7 pentagonal bipyramids. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(11), one Br(16), one Br(2), one Br(5), one Br(6), and one Br(7) atom. In the second La site, La(2) is bonded to one Br(12), one Br(17), one Br(18), one Br(3), one Br(4), one Br(8), and one Br(9) atom to form distorted LaBr7 pentagonal bipyramids that share corners with two equivalent Sr(1)Br7 pentagonal bipyramids, corners with two equivalent Sr(3)Br7 pentagonal bipyramids,  an edgeedge with one Sr(6)Br7 pentagonal bipyramid, and edges with two equivalent Sr(3)Br7 pentagonal bipyramids. There are eighteen inequivalent Br sites. In the first Br site, Br(1) is bonded to one Sr(1), one Sr(4), one Sr(6), and one La(1) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the second Br site, Br(2) is bonded to one Sr(2), one Sr(4), one Sr(5), and one La(1) atom to form a mixture of distorted corner and edge-sharing BrSr3La tetrahedra. In the third Br site, Br(3) is bonded to one Sr(2), one Sr(3), one Sr(5), and one La(2) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the fourth Br site, Br(4) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(6), and one La(2) atom. In the fifth Br site, Br(5) is bonded in a trigonal planar geometry to one Sr(1), one Sr(6), and one La(1) atom. In the sixth Br site, Br(6) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(5), and one La(1) atom. In the seventh Br site, Br(7) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(4), and one La(1) atom. In the eighth Br site, Br(8) is bonded in a trigonal planar geometry to one Sr(2), one Sr(3), and one La(2) atom. In the ninth Br site, Br(9) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(3), and one La(2) atom. In the tenth Br site, Br(10) is bonded to one Sr(1), one Sr(4), one Sr(6), and one La(1) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the eleventh Br site, Br(11) is bonded to one Sr(2), one Sr(4), one Sr(5), and one La(1) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the twelfth Br site, Br(12) is bonded to one Sr(2), one Sr(3), one Sr(5), and one La(2) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the thirteenth Br site, Br(13) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(3), and one Sr(6) atom. In the fourteenth Br site, Br(14) is bonded in a trigonal planar geometry to one Sr(1), one Sr(4), and one Sr(6) atom. In the fifteenth Br site, Br(15) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(4), and one Sr(5) atom. In the sixteenth Br site, Br(16) is bonded in a distorted trigonal non-coplanar geometry to one Sr(4), one Sr(5), and one La(1) atom. In the seventeenth Br site, Br(17) is bonded in a trigonal planar geometry to one Sr(3), one Sr(5), and one La(2) atom. In the eighteenth Br site, Br(18) is bonded in a trigonal non-coplanar geometry to one Sr(3), one Sr(6), and one La(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr3LaBr9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.270
_cell_length_b   7.811
_cell_length_c   30.661
_cell_angle_alpha   88.086
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1740.029
_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
  Sr  Sr0  1  0.970  0.672  0.933  1.0
  Sr  Sr1  1  0.003  0.704  0.692  1.0
  Sr  Sr2  1  0.030  0.672  0.433  1.0
  Sr  Sr3  1  0.997  0.704  0.192  1.0
  Sr  Sr4  1  0.988  0.317  0.569  1.0
  Sr  Sr5  1  0.985  0.283  0.809  1.0
  Sr  Sr6  1  0.012  0.317  0.069  1.0
  Sr  Sr7  1  0.015  0.283  0.309  1.0
  Sr  Sr8  1  0.521  0.215  0.692  1.0
  Sr  Sr9  1  0.515  0.177  0.932  1.0
  Sr  Sr10  1  0.479  0.215  0.192  1.0
  Sr  Sr11  1  0.485  0.177  0.432  1.0
  La  La12  1  0.521  0.796  0.807  1.0
  La  La13  1  0.545  0.820  0.567  1.0
  La  La14  1  0.479  0.796  0.307  1.0
  La  La15  1  0.455  0.820  0.067  1.0
  Br  Br16  1  0.800  0.984  0.870  1.0
  Br  Br17  1  0.821  0.990  0.751  1.0
  Br  Br18  1  0.818  0.998  0.629  1.0
  Br  Br19  1  0.200  0.984  0.370  1.0
  Br  Br20  1  0.179  0.990  0.251  1.0
  Br  Br21  1  0.710  0.892  0.991  1.0
  Br  Br22  1  0.182  0.998  0.129  1.0
  Br  Br23  1  0.326  0.850  0.895  1.0
  Br  Br24  1  0.290  0.892  0.491  1.0
  Br  Br25  1  0.393  0.844  0.706  1.0
  Br  Br26  1  0.674  0.850  0.395  1.0
  Br  Br27  1  0.607  0.844  0.206  1.0
  Br  Br28  1  0.152  0.643  0.796  1.0
  Br  Br29  1  0.200  0.646  0.600  1.0
  Br  Br30  1  0.848  0.643  0.296  1.0
  Br  Br31  1  0.800  0.646  0.100  1.0
  Br  Br32  1  0.753  0.584  0.510  1.0
  Br  Br33  1  0.683  0.502  0.868  1.0
  Br  Br34  1  0.695  0.506  0.751  1.0
  Br  Br35  1  0.702  0.517  0.629  1.0
  Br  Br36  1  0.247  0.584  0.010  1.0
  Br  Br37  1  0.317  0.502  0.368  1.0
  Br  Br38  1  0.305  0.506  0.251  1.0
  Br  Br39  1  0.298  0.517  0.129  1.0
  Br  Br40  1  0.762  0.395  0.989  1.0
  Br  Br41  1  0.238  0.395  0.489  1.0
  Br  Br42  1  0.157  0.345  0.900  1.0
  Br  Br43  1  0.119  0.329  0.699  1.0
  Br  Br44  1  0.843  0.345  0.400  1.0
  Br  Br45  1  0.881  0.329  0.199  1.0
  Br  Br46  1  0.387  0.154  0.797  1.0
  Br  Br47  1  0.350  0.133  0.599  1.0
  Br  Br48  1  0.613  0.154  0.297  1.0
  Br  Br49  1  0.650  0.133  0.099  1.0
  Br  Br50  1  0.758  0.074  0.510  1.0
  Br  Br51  1  0.242  0.074  0.010  1.0
[/CIF]
.
The crystal structure described by Sr3LaBr9 crystallizes in the monoclinic Pc space group. There are six inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one Br(1), one Br(10), one Br(13), one Br(14), one Br(4), one Br(5), and one Br(9) atom to form distorted SrBr7 pentagonal bipyramids that share corners with two equivalent Sr(6)Br7 pentagonal bipyramids, corners with two equivalent La(2)Br7 pentagonal bipyramids,  an edgeedge with one Sr(3)Br7 pentagonal bipyramid, and edges with two equivalent Sr(6)Br7 pentagonal bipyramids. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one Br(11), one Br(12), one Br(15), one Br(2), one Br(3), one Br(6), one Br(7), and one Br(8) atom. In the third Sr site, Sr(3) is bonded to one Br(12), one Br(13), one Br(17), one Br(18), one Br(3), one Br(8), and one Br(9) atom to form distorted SrBr7 pentagonal bipyramids that share corners with two equivalent Sr(6)Br7 pentagonal bipyramids, corners with two equivalent La(2)Br7 pentagonal bipyramids,  an edgeedge with one Sr(1)Br7 pentagonal bipyramid, and edges with two equivalent La(2)Br7 pentagonal bipyramids. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(11), one Br(14), one Br(15), one Br(16), one Br(2), and one Br(7) atom. In the fifth Sr site, Sr(5) is bonded in a 8-coordinate geometry to one Br(11), one Br(12), one Br(15), one Br(16), one Br(17), one Br(2), one Br(3), and one Br(6) atom. In the sixth Sr site, Sr(6) is bonded to one Br(1), one Br(10), one Br(13), one Br(14), one Br(18), one Br(4), and one Br(5) atom to form distorted SrBr7 pentagonal bipyramids that share corners with two equivalent Sr(1)Br7 pentagonal bipyramids, corners with two equivalent Sr(3)Br7 pentagonal bipyramids,  an edgeedge with one La(2)Br7 pentagonal bipyramid, and edges with two equivalent Sr(1)Br7 pentagonal bipyramids. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to one Br(1), one Br(10), one Br(11), one Br(16), one Br(2), one Br(5), one Br(6), and one Br(7) atom. In the second La site, La(2) is bonded to one Br(12), one Br(17), one Br(18), one Br(3), one Br(4), one Br(8), and one Br(9) atom to form distorted LaBr7 pentagonal bipyramids that share corners with two equivalent Sr(1)Br7 pentagonal bipyramids, corners with two equivalent Sr(3)Br7 pentagonal bipyramids,  an edgeedge with one Sr(6)Br7 pentagonal bipyramid, and edges with two equivalent Sr(3)Br7 pentagonal bipyramids. There are eighteen inequivalent Br sites. In the first Br site, Br(1) is bonded to one Sr(1), one Sr(4), one Sr(6), and one La(1) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the second Br site, Br(2) is bonded to one Sr(2), one Sr(4), one Sr(5), and one La(1) atom to form a mixture of distorted corner and edge-sharing BrSr3La tetrahedra. In the third Br site, Br(3) is bonded to one Sr(2), one Sr(3), one Sr(5), and one La(2) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the fourth Br site, Br(4) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(6), and one La(2) atom. In the fifth Br site, Br(5) is bonded in a trigonal planar geometry to one Sr(1), one Sr(6), and one La(1) atom. In the sixth Br site, Br(6) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(5), and one La(1) atom. In the seventh Br site, Br(7) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(4), and one La(1) atom. In the eighth Br site, Br(8) is bonded in a trigonal planar geometry to one Sr(2), one Sr(3), and one La(2) atom. In the ninth Br site, Br(9) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(3), and one La(2) atom. In the tenth Br site, Br(10) is bonded to one Sr(1), one Sr(4), one Sr(6), and one La(1) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the eleventh Br site, Br(11) is bonded to one Sr(2), one Sr(4), one Sr(5), and one La(1) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the twelfth Br site, Br(12) is bonded to one Sr(2), one Sr(3), one Sr(5), and one La(2) atom to form a mixture of corner and edge-sharing BrSr3La tetrahedra. In the thirteenth Br site, Br(13) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(3), and one Sr(6) atom. In the fourteenth Br site, Br(14) is bonded in a trigonal planar geometry to one Sr(1), one Sr(4), and one Sr(6) atom. In the fifteenth Br site, Br(15) is bonded in a distorted trigonal non-coplanar geometry to one Sr(2), one Sr(4), and one Sr(5) atom. In the sixteenth Br site, Br(16) is bonded in a distorted trigonal non-coplanar geometry to one Sr(4), one Sr(5), and one La(1) atom. In the seventeenth Br site, Br(17) is bonded in a trigonal planar geometry to one Sr(3), one Sr(5), and one La(2) atom. In the eighteenth Br site, Br(18) is bonded in a trigonal non-coplanar geometry to one Sr(3), one Sr(6), and one La(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr3LaBr9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.270
_cell_length_b   7.811
_cell_length_c   30.661
_cell_angle_alpha   88.086
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1740.029
_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
  Sr  Sr0  1  0.970  0.672  0.933  1.0
  Sr  Sr1  1  0.003  0.704  0.692  1.0
  Sr  Sr2  1  0.030  0.672  0.433  1.0
  Sr  Sr3  1  0.997  0.704  0.192  1.0
  Sr  Sr4  1  0.988  0.317  0.569  1.0
  Sr  Sr5  1  0.985  0.283  0.809  1.0
  Sr  Sr6  1  0.012  0.317  0.069  1.0
  Sr  Sr7  1  0.015  0.283  0.309  1.0
  Sr  Sr8  1  0.521  0.215  0.692  1.0
  Sr  Sr9  1  0.515  0.177  0.932  1.0
  Sr  Sr10  1  0.479  0.215  0.192  1.0
  Sr  Sr11  1  0.485  0.177  0.432  1.0
  La  La12  1  0.521  0.796  0.807  1.0
  La  La13  1  0.545  0.820  0.567  1.0
  La  La14  1  0.479  0.796  0.307  1.0
  La  La15  1  0.455  0.820  0.067  1.0
  Br  Br16  1  0.800  0.984  0.870  1.0
  Br  Br17  1  0.821  0.990  0.751  1.0
  Br  Br18  1  0.818  0.998  0.629  1.0
  Br  Br19  1  0.200  0.984  0.370  1.0
  Br  Br20  1  0.179  0.990  0.251  1.0
  Br  Br21  1  0.710  0.892  0.991  1.0
  Br  Br22  1  0.182  0.998  0.129  1.0
  Br  Br23  1  0.326  0.850  0.895  1.0
  Br  Br24  1  0.290  0.892  0.491  1.0
  Br  Br25  1  0.393  0.844  0.706  1.0
  Br  Br26  1  0.674  0.850  0.395  1.0
  Br  Br27  1  0.607  0.844  0.206  1.0
  Br  Br28  1  0.152  0.643  0.796  1.0
  Br  Br29  1  0.200  0.646  0.600  1.0
  Br  Br30  1  0.848  0.643  0.296  1.0
  Br  Br31  1  0.800  0.646  0.100  1.0
  Br  Br32  1  0.753  0.584  0.510  1.0
  Br  Br33  1  0.683  0.502  0.868  1.0
  Br  Br34  1  0.695  0.506  0.751  1.0
  Br  Br35  1  0.702  0.517  0.629  1.0
  Br  Br36  1  0.247  0.584  0.010  1.0
  Br  Br37  1  0.317  0.502  0.368  1.0
  Br  Br38  1  0.305  0.506  0.251  1.0
  Br  Br39  1  0.298  0.517  0.129  1.0
  Br  Br40  1  0.762  0.395  0.989  1.0
  Br  Br41  1  0.238  0.395  0.489  1.0
  Br  Br42  1  0.157  0.345  0.900  1.0
  Br  Br43  1  0.119  0.329  0.699  1.0
  Br  Br44  1  0.843  0.345  0.400  1.0
  Br  Br45  1  0.881  0.329  0.199  1.0
  Br  Br46  1  0.387  0.154  0.797  1.0
  Br  Br47  1  0.350  0.133  0.599  1.0
  Br  Br48  1  0.613  0.154  0.297  1.0
  Br  Br49  1  0.650  0.133  0.099  1.0
  Br  Br50  1  0.758  0.074  0.510  1.0
  Br  Br51  1  0.242  0.074  0.010  1.0
[/CIF]
.