The material described by Sm2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), three equivalent O(2), and three equivalent O(5) atoms. In the second Sm site, Sm(2) is bonded to one O(1), three equivalent O(3), and three equivalent O(4) atoms to form distorted SmO7 hexagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, edges with six equivalent Sm(2)O7 hexagonal pyramids, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Sm(2)O7 hexagonal pyramids and  an edgeedge with one Sm(2)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Sm(1) and one Si(1) atom. In the third O site, O(3) is bonded to one Sm(1) and three equivalent Sm(2) atoms to form a mixture of corner and edge-sharing OSm4 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to three equivalent Sm(2) and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent Sm(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.125
_cell_length_b   6.802
_cell_length_c   9.192
_cell_angle_alpha   72.212
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   424.202
_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
  Sm  Sm0  1  0.352  0.412  0.388  1.0
  Sm  Sm1  1  0.648  0.588  0.612  1.0
  Sm  Sm2  1  0.852  0.088  0.612  1.0
  Sm  Sm3  1  0.148  0.912  0.388  1.0
  Sm  Sm4  1  0.376  0.266  0.025  1.0
  Sm  Sm5  1  0.624  0.734  0.975  1.0
  Sm  Sm6  1  0.876  0.234  0.975  1.0
  Sm  Sm7  1  0.124  0.766  0.025  1.0
  Si  Si8  1  0.914  0.458  0.298  1.0
  Si  Si9  1  0.086  0.542  0.702  1.0
  Si  Si10  1  0.414  0.042  0.702  1.0
  Si  Si11  1  0.586  0.958  0.298  1.0
  O  O12  1  0.431  0.139  0.296  1.0
  O  O13  1  0.569  0.861  0.704  1.0
  O  O14  1  0.931  0.361  0.704  1.0
  O  O15  1  0.069  0.639  0.296  1.0
  O  O16  1  0.235  0.056  0.595  1.0
  O  O17  1  0.765  0.944  0.405  1.0
  O  O18  1  0.735  0.444  0.405  1.0
  O  O19  1  0.265  0.556  0.595  1.0
  O  O20  1  0.121  0.049  0.117  1.0
  O  O21  1  0.879  0.951  0.883  1.0
  O  O22  1  0.621  0.451  0.883  1.0
  O  O23  1  0.379  0.549  0.117  1.0
  O  O24  1  0.137  0.493  0.884  1.0
  O  O25  1  0.863  0.507  0.116  1.0
  O  O26  1  0.637  0.007  0.116  1.0
  O  O27  1  0.363  0.993  0.884  1.0
  O  O28  1  0.041  0.251  0.365  1.0
  O  O29  1  0.959  0.749  0.635  1.0
  O  O30  1  0.541  0.249  0.635  1.0
  O  O31  1  0.459  0.751  0.365  1.0
[/CIF]
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The material described by Sm2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), three equivalent O(2), and three equivalent O(5) atoms. In the second Sm site, Sm(2) is bonded to one O(1), three equivalent O(3), and three equivalent O(4) atoms to form distorted SmO7 hexagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, edges with six equivalent Sm(2)O7 hexagonal pyramids, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Sm(2)O7 hexagonal pyramids and  an edgeedge with one Sm(2)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sm(2), two equivalent Sm(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Sm(1) and one Si(1) atom. In the third O site, O(3) is bonded to one Sm(1) and three equivalent Sm(2) atoms to form a mixture of corner and edge-sharing OSm4 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to three equivalent Sm(2) and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent Sm(1) and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.125
_cell_length_b   6.802
_cell_length_c   9.192
_cell_angle_alpha   72.212
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   424.202
_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
  Sm  Sm0  1  0.352  0.412  0.388  1.0
  Sm  Sm1  1  0.648  0.588  0.612  1.0
  Sm  Sm2  1  0.852  0.088  0.612  1.0
  Sm  Sm3  1  0.148  0.912  0.388  1.0
  Sm  Sm4  1  0.376  0.266  0.025  1.0
  Sm  Sm5  1  0.624  0.734  0.975  1.0
  Sm  Sm6  1  0.876  0.234  0.975  1.0
  Sm  Sm7  1  0.124  0.766  0.025  1.0
  Si  Si8  1  0.914  0.458  0.298  1.0
  Si  Si9  1  0.086  0.542  0.702  1.0
  Si  Si10  1  0.414  0.042  0.702  1.0
  Si  Si11  1  0.586  0.958  0.298  1.0
  O  O12  1  0.431  0.139  0.296  1.0
  O  O13  1  0.569  0.861  0.704  1.0
  O  O14  1  0.931  0.361  0.704  1.0
  O  O15  1  0.069  0.639  0.296  1.0
  O  O16  1  0.235  0.056  0.595  1.0
  O  O17  1  0.765  0.944  0.405  1.0
  O  O18  1  0.735  0.444  0.405  1.0
  O  O19  1  0.265  0.556  0.595  1.0
  O  O20  1  0.121  0.049  0.117  1.0
  O  O21  1  0.879  0.951  0.883  1.0
  O  O22  1  0.621  0.451  0.883  1.0
  O  O23  1  0.379  0.549  0.117  1.0
  O  O24  1  0.137  0.493  0.884  1.0
  O  O25  1  0.863  0.507  0.116  1.0
  O  O26  1  0.637  0.007  0.116  1.0
  O  O27  1  0.363  0.993  0.884  1.0
  O  O28  1  0.041  0.251  0.365  1.0
  O  O29  1  0.959  0.749  0.635  1.0
  O  O30  1  0.541  0.249  0.635  1.0
  O  O31  1  0.459  0.751  0.365  1.0
[/CIF]
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