The compound described by La2SiO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. In the second La site, La(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent La(2) and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent La(1) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Si(1) atom. In the fifth O site, O(5) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form edge-sharing OLa4 tetrahedra. is represented by the CIF card [CIF]
data_La2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.211
_cell_length_b   8.211
_cell_length_c   11.054
_cell_angle_alpha   61.783
_cell_angle_beta   61.783
_cell_angle_gamma   50.828
_symmetry_Int_Tables_number   1
_cell_volume   492.328
_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
  La  La0  1  0.769  0.523  0.668  1.0
  La  La1  1  0.213  0.713  0.963  1.0
  La  La2  1  0.287  0.787  0.537  1.0
  La  La3  1  0.523  0.769  0.168  1.0
  La  La4  1  0.477  0.231  0.832  1.0
  La  La5  1  0.713  0.213  0.463  1.0
  La  La6  1  0.787  0.287  0.037  1.0
  La  La7  1  0.231  0.477  0.332  1.0
  Si  Si8  1  0.737  0.906  0.312  1.0
  Si  Si9  1  0.094  0.263  0.188  1.0
  Si  Si10  1  0.906  0.737  0.812  1.0
  Si  Si11  1  0.263  0.094  0.688  1.0
  O  O12  1  0.918  0.890  0.158  1.0
  O  O13  1  0.135  0.248  0.562  1.0
  O  O14  1  0.397  0.839  0.687  1.0
  O  O15  1  0.163  0.424  0.165  1.0
  O  O16  1  0.576  0.837  0.335  1.0
  O  O17  1  0.572  0.395  0.895  1.0
  O  O18  1  0.605  0.428  0.605  1.0
  O  O19  1  0.110  0.082  0.342  1.0
  O  O20  1  0.248  0.135  0.062  1.0
  O  O21  1  0.161  0.603  0.813  1.0
  O  O22  1  0.839  0.397  0.187  1.0
  O  O23  1  0.752  0.865  0.938  1.0
  O  O24  1  0.890  0.918  0.658  1.0
  O  O25  1  0.395  0.572  0.395  1.0
  O  O26  1  0.428  0.605  0.105  1.0
  O  O27  1  0.424  0.163  0.665  1.0
  O  O28  1  0.837  0.576  0.835  1.0
  O  O29  1  0.603  0.161  0.313  1.0
  O  O30  1  0.865  0.752  0.438  1.0
  O  O31  1  0.082  0.110  0.842  1.0
[/CIF]
.
The compound described by La2SiO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. In the second La site, La(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to two equivalent La(2) and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent La(1) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Si(1) atom. In the fifth O site, O(5) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form edge-sharing OLa4 tetrahedra. is represented by the CIF card [CIF]
data_La2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.211
_cell_length_b   8.211
_cell_length_c   11.054
_cell_angle_alpha   61.783
_cell_angle_beta   61.783
_cell_angle_gamma   50.828
_symmetry_Int_Tables_number   1
_cell_volume   492.328
_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
  La  La0  1  0.769  0.523  0.668  1.0
  La  La1  1  0.213  0.713  0.963  1.0
  La  La2  1  0.287  0.787  0.537  1.0
  La  La3  1  0.523  0.769  0.168  1.0
  La  La4  1  0.477  0.231  0.832  1.0
  La  La5  1  0.713  0.213  0.463  1.0
  La  La6  1  0.787  0.287  0.037  1.0
  La  La7  1  0.231  0.477  0.332  1.0
  Si  Si8  1  0.737  0.906  0.312  1.0
  Si  Si9  1  0.094  0.263  0.188  1.0
  Si  Si10  1  0.906  0.737  0.812  1.0
  Si  Si11  1  0.263  0.094  0.688  1.0
  O  O12  1  0.918  0.890  0.158  1.0
  O  O13  1  0.135  0.248  0.562  1.0
  O  O14  1  0.397  0.839  0.687  1.0
  O  O15  1  0.163  0.424  0.165  1.0
  O  O16  1  0.576  0.837  0.335  1.0
  O  O17  1  0.572  0.395  0.895  1.0
  O  O18  1  0.605  0.428  0.605  1.0
  O  O19  1  0.110  0.082  0.342  1.0
  O  O20  1  0.248  0.135  0.062  1.0
  O  O21  1  0.161  0.603  0.813  1.0
  O  O22  1  0.839  0.397  0.187  1.0
  O  O23  1  0.752  0.865  0.938  1.0
  O  O24  1  0.890  0.918  0.658  1.0
  O  O25  1  0.395  0.572  0.395  1.0
  O  O26  1  0.428  0.605  0.105  1.0
  O  O27  1  0.424  0.163  0.665  1.0
  O  O28  1  0.837  0.576  0.835  1.0
  O  O29  1  0.603  0.161  0.313  1.0
  O  O30  1  0.865  0.752  0.438  1.0
  O  O31  1  0.082  0.110  0.842  1.0
[/CIF]
.