The structure described by CrAl2O5 crystallizes in the monoclinic C2 space group. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with three equivalent Al(1)O6 octahedra, corners with three equivalent Al(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with two equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-61°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form distorted AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra,  an edgeedge with one Al(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and  a faceface with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the second Al site, Al(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form distorted AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and  a faceface with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded to one Cr(1), one Al(2), and two equivalent Al(1) atoms to form OAl3Cr trigonal pyramids that share  a cornercorner with one O(5)Al2Cr2 trigonal pyramid, corners with three equivalent O(3)Al3Cr trigonal pyramids,  an edgeedge with one O(5)Al2Cr2 trigonal pyramid,  an edgeedge with one O(6)Al2Cr2 trigonal pyramid,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(3)Al3Cr trigonal pyramid. In the third O site, O(3) is bonded to one Cr(1), one Al(1), and two equivalent Al(2) atoms to form OAl3Cr trigonal pyramids that share  a cornercorner with one O(6)Al2Cr2 trigonal pyramid, corners with three equivalent O(2)Al3Cr trigonal pyramids,  an edgeedge with one O(5)Al2Cr2 trigonal pyramid,  an edgeedge with one O(6)Al2Cr2 trigonal pyramid,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(3)Al3Cr trigonal pyramid. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Al(2) atoms. In the fifth O site, O(5) is bonded to two equivalent Cr(1) and two equivalent Al(1) atoms to form distorted OAl2Cr2 trigonal pyramids that share corners with two equivalent O(6)Al2Cr2 trigonal pyramids, corners with two equivalent O(2)Al3Cr trigonal pyramids, edges with two equivalent O(2)Al3Cr trigonal pyramids, and edges with two equivalent O(3)Al3Cr trigonal pyramids. In the sixth O site, O(6) is bonded to two equivalent Cr(1) and two equivalent Al(2) atoms to form distorted OAl2Cr2 trigonal pyramids that share corners with two equivalent O(5)Al2Cr2 trigonal pyramids, corners with two equivalent O(3)Al3Cr trigonal pyramids, edges with two equivalent O(2)Al3Cr trigonal pyramids, and edges with two equivalent O(3)Al3Cr trigonal pyramids. is represented by the CIF card [CIF]
data_Al2CrO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.965
_cell_length_b   5.385
_cell_length_c   6.838
_cell_angle_alpha   70.881
_cell_angle_beta   89.993
_cell_angle_gamma   62.544
_symmetry_Int_Tables_number   1
_cell_volume   150.793
_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
  Al  Al0  1  0.640  0.742  0.713  1.0
  Al  Al1  1  0.383  0.256  0.783  1.0
  Al  Al2  1  0.617  0.741  0.213  1.0
  Al  Al3  1  0.359  0.256  0.283  1.0
  Cr  Cr4  1  1.000  0.998  0.498  1.0
  Cr  Cr5  1  0.999  0.999  0.998  1.0
  O  O6  1  0.036  0.621  0.653  1.0
  O  O7  1  0.736  0.830  0.945  1.0
  O  O8  1  0.432  0.830  0.444  1.0
  O  O9  1  0.659  0.377  0.843  1.0
  O  O10  1  0.339  0.621  0.154  1.0
  O  O11  1  0.200  0.999  0.748  1.0
  O  O12  1  0.567  0.167  0.552  1.0
  O  O13  1  0.263  0.168  0.051  1.0
  O  O14  1  0.962  0.376  0.342  1.0
  O  O15  1  0.798  0.999  0.248  1.0
[/CIF]
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The structure described by CrAl2O5 crystallizes in the monoclinic C2 space group. Cr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with three equivalent Al(1)O6 octahedra, corners with three equivalent Al(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with two equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-61°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form distorted AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra,  an edgeedge with one Al(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and  a faceface with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the second Al site, Al(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form distorted AlO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and  a faceface with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded to one Cr(1), one Al(2), and two equivalent Al(1) atoms to form OAl3Cr trigonal pyramids that share  a cornercorner with one O(5)Al2Cr2 trigonal pyramid, corners with three equivalent O(3)Al3Cr trigonal pyramids,  an edgeedge with one O(5)Al2Cr2 trigonal pyramid,  an edgeedge with one O(6)Al2Cr2 trigonal pyramid,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(3)Al3Cr trigonal pyramid. In the third O site, O(3) is bonded to one Cr(1), one Al(1), and two equivalent Al(2) atoms to form OAl3Cr trigonal pyramids that share  a cornercorner with one O(6)Al2Cr2 trigonal pyramid, corners with three equivalent O(2)Al3Cr trigonal pyramids,  an edgeedge with one O(5)Al2Cr2 trigonal pyramid,  an edgeedge with one O(6)Al2Cr2 trigonal pyramid,  an edgeedge with one O(2)Al3Cr trigonal pyramid, and  an edgeedge with one O(3)Al3Cr trigonal pyramid. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Al(2) atoms. In the fifth O site, O(5) is bonded to two equivalent Cr(1) and two equivalent Al(1) atoms to form distorted OAl2Cr2 trigonal pyramids that share corners with two equivalent O(6)Al2Cr2 trigonal pyramids, corners with two equivalent O(2)Al3Cr trigonal pyramids, edges with two equivalent O(2)Al3Cr trigonal pyramids, and edges with two equivalent O(3)Al3Cr trigonal pyramids. In the sixth O site, O(6) is bonded to two equivalent Cr(1) and two equivalent Al(2) atoms to form distorted OAl2Cr2 trigonal pyramids that share corners with two equivalent O(5)Al2Cr2 trigonal pyramids, corners with two equivalent O(3)Al3Cr trigonal pyramids, edges with two equivalent O(2)Al3Cr trigonal pyramids, and edges with two equivalent O(3)Al3Cr trigonal pyramids. is represented by the CIF card [CIF]
data_Al2CrO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.965
_cell_length_b   5.385
_cell_length_c   6.838
_cell_angle_alpha   70.881
_cell_angle_beta   89.993
_cell_angle_gamma   62.544
_symmetry_Int_Tables_number   1
_cell_volume   150.793
_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
  Al  Al0  1  0.640  0.742  0.713  1.0
  Al  Al1  1  0.383  0.256  0.783  1.0
  Al  Al2  1  0.617  0.741  0.213  1.0
  Al  Al3  1  0.359  0.256  0.283  1.0
  Cr  Cr4  1  1.000  0.998  0.498  1.0
  Cr  Cr5  1  0.999  0.999  0.998  1.0
  O  O6  1  0.036  0.621  0.653  1.0
  O  O7  1  0.736  0.830  0.945  1.0
  O  O8  1  0.432  0.830  0.444  1.0
  O  O9  1  0.659  0.377  0.843  1.0
  O  O10  1  0.339  0.621  0.154  1.0
  O  O11  1  0.200  0.999  0.748  1.0
  O  O12  1  0.567  0.167  0.552  1.0
  O  O13  1  0.263  0.168  0.051  1.0
  O  O14  1  0.962  0.376  0.342  1.0
  O  O15  1  0.798  0.999  0.248  1.0
[/CIF]
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