The crystal structure described by Er2SiO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted ErO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra and edges with two equivalent Er(1)O6 octahedra. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Er(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-69°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Er(1), one Er(2), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Er(1), two equivalent Er(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Er(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Er(1) and one Si(1) atom. In the fifth O site, O(5) is bonded to two equivalent Er(1) and two equivalent Er(2) atoms to form edge-sharing OEr4 tetrahedra. is represented by the CIF file [CIF]
data_Er2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.896
_cell_length_b   7.896
_cell_length_c   10.279
_cell_angle_alpha   61.158
_cell_angle_beta   61.158
_cell_angle_gamma   49.930
_symmetry_Int_Tables_number   1
_cell_volume   415.263
_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
  Er  Er0  1  0.483  0.235  0.336  1.0
  Er  Er1  1  0.219  0.708  0.466  1.0
  Er  Er2  1  0.517  0.765  0.664  1.0
  Er  Er3  1  0.235  0.483  0.836  1.0
  Er  Er4  1  0.765  0.517  0.164  1.0
  Er  Er5  1  0.781  0.292  0.534  1.0
  Er  Er6  1  0.708  0.219  0.966  1.0
  Er  Er7  1  0.292  0.781  0.034  1.0
  Si  Si8  1  0.727  0.909  0.808  1.0
  Si  Si9  1  0.273  0.091  0.192  1.0
  Si  Si10  1  0.091  0.273  0.692  1.0
  Si  Si11  1  0.909  0.727  0.308  1.0
  O  O12  1  0.446  0.150  0.175  1.0
  O  O13  1  0.830  0.408  0.678  1.0
  O  O14  1  0.914  0.908  0.139  1.0
  O  O15  1  0.271  0.132  0.561  1.0
  O  O16  1  0.554  0.850  0.825  1.0
  O  O17  1  0.385  0.579  0.898  1.0
  O  O18  1  0.150  0.446  0.675  1.0
  O  O19  1  0.408  0.830  0.178  1.0
  O  O20  1  0.729  0.868  0.439  1.0
  O  O21  1  0.579  0.385  0.398  1.0
  O  O22  1  0.421  0.615  0.602  1.0
  O  O23  1  0.092  0.086  0.361  1.0
  O  O24  1  0.170  0.592  0.322  1.0
  O  O25  1  0.868  0.729  0.939  1.0
  O  O26  1  0.908  0.914  0.639  1.0
  O  O27  1  0.850  0.554  0.325  1.0
  O  O28  1  0.086  0.092  0.861  1.0
  O  O29  1  0.615  0.421  0.102  1.0
  O  O30  1  0.592  0.170  0.822  1.0
  O  O31  1  0.132  0.271  0.061  1.0
[/CIF]
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The crystal structure described by Er2SiO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted ErO6 octahedra that share corners with four equivalent Si(1)O4 tetrahedra and edges with two equivalent Er(1)O6 octahedra. In the second Er site, Er(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with four equivalent Er(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-69°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Er(1), one Er(2), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Er(1), two equivalent Er(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Er(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Er(1) and one Si(1) atom. In the fifth O site, O(5) is bonded to two equivalent Er(1) and two equivalent Er(2) atoms to form edge-sharing OEr4 tetrahedra. is represented by the CIF file [CIF]
data_Er2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.896
_cell_length_b   7.896
_cell_length_c   10.279
_cell_angle_alpha   61.158
_cell_angle_beta   61.158
_cell_angle_gamma   49.930
_symmetry_Int_Tables_number   1
_cell_volume   415.263
_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
  Er  Er0  1  0.483  0.235  0.336  1.0
  Er  Er1  1  0.219  0.708  0.466  1.0
  Er  Er2  1  0.517  0.765  0.664  1.0
  Er  Er3  1  0.235  0.483  0.836  1.0
  Er  Er4  1  0.765  0.517  0.164  1.0
  Er  Er5  1  0.781  0.292  0.534  1.0
  Er  Er6  1  0.708  0.219  0.966  1.0
  Er  Er7  1  0.292  0.781  0.034  1.0
  Si  Si8  1  0.727  0.909  0.808  1.0
  Si  Si9  1  0.273  0.091  0.192  1.0
  Si  Si10  1  0.091  0.273  0.692  1.0
  Si  Si11  1  0.909  0.727  0.308  1.0
  O  O12  1  0.446  0.150  0.175  1.0
  O  O13  1  0.830  0.408  0.678  1.0
  O  O14  1  0.914  0.908  0.139  1.0
  O  O15  1  0.271  0.132  0.561  1.0
  O  O16  1  0.554  0.850  0.825  1.0
  O  O17  1  0.385  0.579  0.898  1.0
  O  O18  1  0.150  0.446  0.675  1.0
  O  O19  1  0.408  0.830  0.178  1.0
  O  O20  1  0.729  0.868  0.439  1.0
  O  O21  1  0.579  0.385  0.398  1.0
  O  O22  1  0.421  0.615  0.602  1.0
  O  O23  1  0.092  0.086  0.361  1.0
  O  O24  1  0.170  0.592  0.322  1.0
  O  O25  1  0.868  0.729  0.939  1.0
  O  O26  1  0.908  0.914  0.639  1.0
  O  O27  1  0.850  0.554  0.325  1.0
  O  O28  1  0.086  0.092  0.861  1.0
  O  O29  1  0.615  0.421  0.102  1.0
  O  O30  1  0.592  0.170  0.822  1.0
  O  O31  1  0.132  0.271  0.061  1.0
[/CIF]
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