The crystal structure described by Er2TiCuO6 crystallizes in the trigonal P3m1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(5) atoms. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(2), and three equivalent O(6) atoms. Ti(1) is bonded to one O(1), one O(6), and three equivalent O(3) atoms to form corner-sharing TiO5 trigonal bipyramids. Cu(1) is bonded to one O(2), one O(5), and three equivalent O(4) atoms to form corner-sharing CuO5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to three equivalent Er(1) and one Ti(1) atom. In the second O site, O(2) is bonded to three equivalent Er(2) and one Cu(1) atom to form OEr3Cu tetrahedra that share  a cornercorner with one O(5)Er3Cu tetrahedra, corners with six equivalent O(2)Er3Cu tetrahedra, and edges with three equivalent O(4)Er2Cu3 trigonal bipyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to three equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to one Er(1), one Er(2), and three equivalent Cu(1) atoms to form OEr2Cu3 trigonal bipyramids that share corners with six equivalent O(4)Er2Cu3 trigonal bipyramids, edges with three equivalent O(2)Er3Cu tetrahedra, and edges with three equivalent O(5)Er3Cu tetrahedra. In the fifth O site, O(5) is bonded to three equivalent Er(1) and one Cu(1) atom to form OEr3Cu tetrahedra that share  a cornercorner with one O(2)Er3Cu tetrahedra, corners with six equivalent O(5)Er3Cu tetrahedra, and edges with three equivalent O(4)Er2Cu3 trigonal bipyramids. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to three equivalent Er(2) and one Ti(1) atom. is represented by the CIF card [CIF]
data_Er2TiCuO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.593
_cell_length_b   11.304
_cell_length_c   3.593
_cell_angle_alpha   90.000
_cell_angle_beta   119.996
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   126.396
_cell_formula_units_Z   1
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  1.000  0.272  1.000  1.0
  Er  Er1  1  1.000  0.724  1.000  1.0
  Ti  Ti2  1  0.333  0.998  0.667  1.0
  Cu  Cu3  1  0.667  0.498  0.333  1.0
  O  O4  1  0.333  0.163  0.667  1.0
  O  O5  1  0.667  0.668  0.333  1.0
  O  O6  1  0.000  0.998  0.000  1.0
  O  O7  1  1.000  0.498  1.000  1.0
  O  O8  1  0.667  0.329  0.333  1.0
  O  O9  1  0.333  0.832  0.667  1.0
[/CIF]
.
The crystal structure described by Er2TiCuO6 crystallizes in the trigonal P3m1 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(5) atoms. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(2), and three equivalent O(6) atoms. Ti(1) is bonded to one O(1), one O(6), and three equivalent O(3) atoms to form corner-sharing TiO5 trigonal bipyramids. Cu(1) is bonded to one O(2), one O(5), and three equivalent O(4) atoms to form corner-sharing CuO5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to three equivalent Er(1) and one Ti(1) atom. In the second O site, O(2) is bonded to three equivalent Er(2) and one Cu(1) atom to form OEr3Cu tetrahedra that share  a cornercorner with one O(5)Er3Cu tetrahedra, corners with six equivalent O(2)Er3Cu tetrahedra, and edges with three equivalent O(4)Er2Cu3 trigonal bipyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to three equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded to one Er(1), one Er(2), and three equivalent Cu(1) atoms to form OEr2Cu3 trigonal bipyramids that share corners with six equivalent O(4)Er2Cu3 trigonal bipyramids, edges with three equivalent O(2)Er3Cu tetrahedra, and edges with three equivalent O(5)Er3Cu tetrahedra. In the fifth O site, O(5) is bonded to three equivalent Er(1) and one Cu(1) atom to form OEr3Cu tetrahedra that share  a cornercorner with one O(2)Er3Cu tetrahedra, corners with six equivalent O(5)Er3Cu tetrahedra, and edges with three equivalent O(4)Er2Cu3 trigonal bipyramids. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to three equivalent Er(2) and one Ti(1) atom. is represented by the CIF card [CIF]
data_Er2TiCuO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.593
_cell_length_b   11.304
_cell_length_c   3.593
_cell_angle_alpha   90.000
_cell_angle_beta   119.996
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   126.396
_cell_formula_units_Z   1
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  1.000  0.272  1.000  1.0
  Er  Er1  1  1.000  0.724  1.000  1.0
  Ti  Ti2  1  0.333  0.998  0.667  1.0
  Cu  Cu3  1  0.667  0.498  0.333  1.0
  O  O4  1  0.333  0.163  0.667  1.0
  O  O5  1  0.667  0.668  0.333  1.0
  O  O6  1  0.000  0.998  0.000  1.0
  O  O7  1  1.000  0.498  1.000  1.0
  O  O8  1  0.667  0.329  0.333  1.0
  O  O9  1  0.333  0.832  0.667  1.0
[/CIF]
.