The compound described by EuAl2O4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and two equivalent O(7) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(6), two equivalent O(5), and two equivalent O(8) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form corner-sharing AlO4 tetrahedra. In the fourth Al site, Al(4) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form corner-sharing AlO4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Eu(1), one Eu(2), one Al(2), and one Al(3) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Eu(1), one Eu(2), one Al(1), and one Al(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Eu(1), one Al(2), and one Al(4) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Eu(1), one Eu(2), one Al(1), and one Al(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Eu(2), one Al(2), and one Al(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Eu(1), one Eu(2), one Al(1), and one Al(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Eu(1), one Al(3), and one Al(4) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Eu(2), one Al(1), and one Al(2) atom. is represented by the CIF file [CIF]
data_EuAl2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.787
_cell_length_b   5.159
_cell_length_c   8.416
_cell_angle_alpha   86.647
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   380.842
_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
  Eu  Eu0  1  0.500  0.253  0.510  1.0
  Eu  Eu1  1  1.000  0.747  0.490  1.0
  Eu  Eu2  1  0.493  0.196  0.972  1.0
  Eu  Eu3  1  0.993  0.804  0.028  1.0
  Al  Al4  1  0.330  0.709  0.810  1.0
  Al  Al5  1  0.830  0.291  0.190  1.0
  Al  Al6  1  0.337  0.726  0.201  1.0
  Al  Al7  1  0.837  0.274  0.799  1.0
  Al  Al8  1  0.168  0.220  0.291  1.0
  Al  Al9  1  0.668  0.780  0.709  1.0
  Al  Al10  1  0.670  0.803  0.321  1.0
  Al  Al11  1  0.170  0.197  0.679  1.0
  O  O12  1  0.670  0.439  0.733  1.0
  O  O13  1  0.170  0.561  0.267  1.0
  O  O14  1  0.816  0.593  0.271  1.0
  O  O15  1  0.316  0.407  0.729  1.0
  O  O16  1  0.990  0.343  0.670  1.0
  O  O17  1  0.490  0.657  0.330  1.0
  O  O18  1  0.483  0.899  0.735  1.0
  O  O19  1  0.983  0.101  0.265  1.0
  O  O20  1  0.794  0.940  0.831  1.0
  O  O21  1  0.294  0.060  0.169  1.0
  O  O22  1  0.165  0.901  0.795  1.0
  O  O23  1  0.665  0.099  0.205  1.0
  O  O24  1  0.718  0.889  0.514  1.0
  O  O25  1  0.218  0.111  0.486  1.0
  O  O26  1  0.385  0.638  0.009  1.0
  O  O27  1  0.885  0.362  0.991  1.0
[/CIF]
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The compound described by EuAl2O4 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and two equivalent O(7) atoms. In the second Eu site, Eu(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), one O(6), two equivalent O(5), and two equivalent O(8) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form corner-sharing AlO4 tetrahedra. In the fourth Al site, Al(4) is bonded to one O(2), one O(3), one O(6), and one O(7) atom to form corner-sharing AlO4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Eu(1), one Eu(2), one Al(2), and one Al(3) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Eu(1), one Eu(2), one Al(1), and one Al(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Eu(1), one Al(2), and one Al(4) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Eu(1), one Eu(2), one Al(1), and one Al(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Eu(2), one Al(2), and one Al(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Eu(1), one Eu(2), one Al(1), and one Al(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Eu(1), one Al(3), and one Al(4) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Eu(2), one Al(1), and one Al(2) atom. is represented by the CIF file [CIF]
data_EuAl2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.787
_cell_length_b   5.159
_cell_length_c   8.416
_cell_angle_alpha   86.647
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   380.842
_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
  Eu  Eu0  1  0.500  0.253  0.510  1.0
  Eu  Eu1  1  1.000  0.747  0.490  1.0
  Eu  Eu2  1  0.493  0.196  0.972  1.0
  Eu  Eu3  1  0.993  0.804  0.028  1.0
  Al  Al4  1  0.330  0.709  0.810  1.0
  Al  Al5  1  0.830  0.291  0.190  1.0
  Al  Al6  1  0.337  0.726  0.201  1.0
  Al  Al7  1  0.837  0.274  0.799  1.0
  Al  Al8  1  0.168  0.220  0.291  1.0
  Al  Al9  1  0.668  0.780  0.709  1.0
  Al  Al10  1  0.670  0.803  0.321  1.0
  Al  Al11  1  0.170  0.197  0.679  1.0
  O  O12  1  0.670  0.439  0.733  1.0
  O  O13  1  0.170  0.561  0.267  1.0
  O  O14  1  0.816  0.593  0.271  1.0
  O  O15  1  0.316  0.407  0.729  1.0
  O  O16  1  0.990  0.343  0.670  1.0
  O  O17  1  0.490  0.657  0.330  1.0
  O  O18  1  0.483  0.899  0.735  1.0
  O  O19  1  0.983  0.101  0.265  1.0
  O  O20  1  0.794  0.940  0.831  1.0
  O  O21  1  0.294  0.060  0.169  1.0
  O  O22  1  0.165  0.901  0.795  1.0
  O  O23  1  0.665  0.099  0.205  1.0
  O  O24  1  0.718  0.889  0.514  1.0
  O  O25  1  0.218  0.111  0.486  1.0
  O  O26  1  0.385  0.638  0.009  1.0
  O  O27  1  0.885  0.362  0.991  1.0
[/CIF]
.