The structure described by Er2TiO5 crystallizes in the monoclinic Cc space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms. In the second Er site, Er(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Er(1), one Er(2), and one Ti(1) atom. In the second O site, O(2) is bonded to one Er(2), two equivalent Er(1), and one Ti(1) atom to form distorted OEr3Ti tetrahedra that share corners with two equivalent O(2)Er3Ti tetrahedra,  a cornercorner with one O(4)Er2Ti2 trigonal pyramid, and edges with two equivalent O(4)Er2Ti2 trigonal pyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Er(1), one Er(2), and one Ti(1) atom. In the fourth O site, O(4) is bonded to one Er(1), one Er(2), and two equivalent Ti(1) atoms to form distorted OEr2Ti2 trigonal pyramids that share  a cornercorner with one O(2)Er3Ti tetrahedra, corners with two equivalent O(4)Er2Ti2 trigonal pyramids, and edges with two equivalent O(2)Er3Ti tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Er(1), two equivalent Er(2), and one Ti(1) atom. is represented by the CIF file [CIF]
data_Er2TiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.385
_cell_length_b   6.385
_cell_length_c   7.524
_cell_angle_alpha   68.487
_cell_angle_beta   68.487
_cell_angle_gamma   48.713
_symmetry_Int_Tables_number   1
_cell_volume   210.984
_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
  Er  Er0  1  0.372  0.354  0.751  1.0
  Er  Er1  1  0.647  0.632  0.748  1.0
  Er  Er2  1  0.354  0.372  0.251  1.0
  Er  Er3  1  0.632  0.647  0.248  1.0
  Ti  Ti4  1  0.006  0.995  0.491  1.0
  Ti  Ti5  1  0.995  0.006  0.991  1.0
  O  O6  1  0.976  0.686  0.640  1.0
  O  O7  1  0.248  0.610  0.956  1.0
  O  O8  1  0.610  0.248  0.456  1.0
  O  O9  1  0.315  0.026  0.859  1.0
  O  O10  1  0.686  0.976  0.140  1.0
  O  O11  1  0.831  0.171  0.753  1.0
  O  O12  1  0.392  0.754  0.543  1.0
  O  O13  1  0.754  0.392  0.043  1.0
  O  O14  1  0.026  0.315  0.359  1.0
  O  O15  1  0.171  0.831  0.253  1.0
[/CIF]
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The structure described by Er2TiO5 crystallizes in the monoclinic Cc space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms. In the second Er site, Er(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Er(1), one Er(2), and one Ti(1) atom. In the second O site, O(2) is bonded to one Er(2), two equivalent Er(1), and one Ti(1) atom to form distorted OEr3Ti tetrahedra that share corners with two equivalent O(2)Er3Ti tetrahedra,  a cornercorner with one O(4)Er2Ti2 trigonal pyramid, and edges with two equivalent O(4)Er2Ti2 trigonal pyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Er(1), one Er(2), and one Ti(1) atom. In the fourth O site, O(4) is bonded to one Er(1), one Er(2), and two equivalent Ti(1) atoms to form distorted OEr2Ti2 trigonal pyramids that share  a cornercorner with one O(2)Er3Ti tetrahedra, corners with two equivalent O(4)Er2Ti2 trigonal pyramids, and edges with two equivalent O(2)Er3Ti tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Er(1), two equivalent Er(2), and one Ti(1) atom. is represented by the CIF file [CIF]
data_Er2TiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.385
_cell_length_b   6.385
_cell_length_c   7.524
_cell_angle_alpha   68.487
_cell_angle_beta   68.487
_cell_angle_gamma   48.713
_symmetry_Int_Tables_number   1
_cell_volume   210.984
_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
  Er  Er0  1  0.372  0.354  0.751  1.0
  Er  Er1  1  0.647  0.632  0.748  1.0
  Er  Er2  1  0.354  0.372  0.251  1.0
  Er  Er3  1  0.632  0.647  0.248  1.0
  Ti  Ti4  1  0.006  0.995  0.491  1.0
  Ti  Ti5  1  0.995  0.006  0.991  1.0
  O  O6  1  0.976  0.686  0.640  1.0
  O  O7  1  0.248  0.610  0.956  1.0
  O  O8  1  0.610  0.248  0.456  1.0
  O  O9  1  0.315  0.026  0.859  1.0
  O  O10  1  0.686  0.976  0.140  1.0
  O  O11  1  0.831  0.171  0.753  1.0
  O  O12  1  0.392  0.754  0.543  1.0
  O  O13  1  0.754  0.392  0.043  1.0
  O  O14  1  0.026  0.315  0.359  1.0
  O  O15  1  0.171  0.831  0.253  1.0
[/CIF]
.