The compound described by PrYSi2O7 crystallizes in the monoclinic P2_1/c space group. Pr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(7), two equivalent O(5), and two equivalent O(6) atoms. Y(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), one O(6), one O(7), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Pr(1), one Y(1), and one Si(2) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Pr(1), one Y(1), and one Si(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Pr(1), one Y(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Y(1), and one Si(1) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Y(1), and one Si(1) atom. In the seventh O site, O(4) is bonded in a 3-coordinate geometry to one Pr(1), one Y(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_PrYSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.673
_cell_length_b   5.443
_cell_length_c   13.981
_cell_angle_alpha   67.534
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   609.877
_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
  Pr  Pr0  1  0.809  0.474  0.772  1.0
  Pr  Pr1  1  0.309  0.526  0.728  1.0
  Pr  Pr2  1  0.191  0.526  0.228  1.0
  Pr  Pr3  1  0.691  0.474  0.272  1.0
  Y  Y4  1  0.604  0.174  0.592  1.0
  Y  Y5  1  0.104  0.826  0.908  1.0
  Y  Y6  1  0.396  0.826  0.408  1.0
  Y  Y7  1  0.896  0.174  0.092  1.0
  Si  Si8  1  0.247  0.257  0.021  1.0
  Si  Si9  1  0.747  0.743  0.479  1.0
  Si  Si10  1  0.753  0.743  0.979  1.0
  Si  Si11  1  0.253  0.257  0.521  1.0
  Si  Si12  1  0.506  0.038  0.179  1.0
  Si  Si13  1  0.006  0.962  0.321  1.0
  Si  Si14  1  0.494  0.962  0.821  1.0
  Si  Si15  1  0.994  0.038  0.679  1.0
  O  O16  1  0.422  0.208  0.069  1.0
  O  O17  1  0.922  0.792  0.431  1.0
  O  O18  1  0.578  0.792  0.931  1.0
  O  O19  1  0.078  0.208  0.569  1.0
  O  O20  1  0.157  0.977  0.039  1.0
  O  O21  1  0.657  0.023  0.461  1.0
  O  O22  1  0.843  0.023  0.961  1.0
  O  O23  1  0.343  0.977  0.539  1.0
  O  O24  1  0.136  0.411  0.078  1.0
  O  O25  1  0.636  0.589  0.422  1.0
  O  O26  1  0.864  0.589  0.922  1.0
  O  O27  1  0.364  0.411  0.578  1.0
  O  O28  1  0.250  0.473  0.903  1.0
  O  O29  1  0.750  0.527  0.597  1.0
  O  O30  1  0.750  0.527  0.097  1.0
  O  O31  1  0.250  0.473  0.403  1.0
  O  O32  1  0.489  0.195  0.259  1.0
  O  O33  1  0.989  0.805  0.241  1.0
  O  O34  1  0.511  0.805  0.741  1.0
  O  O35  1  0.011  0.195  0.759  1.0
  O  O36  1  0.423  0.748  0.239  1.0
  O  O37  1  0.923  0.252  0.261  1.0
  O  O38  1  0.577  0.252  0.761  1.0
  O  O39  1  0.077  0.748  0.739  1.0
  O  O40  1  0.684  0.961  0.167  1.0
  O  O41  1  0.184  0.039  0.333  1.0
  O  O42  1  0.316  0.039  0.833  1.0
  O  O43  1  0.816  0.961  0.667  1.0
[/CIF]
.
The compound described by PrYSi2O7 crystallizes in the monoclinic P2_1/c space group. Pr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(7), two equivalent O(5), and two equivalent O(6) atoms. Y(1) is bonded in a 8-coordinate geometry to one O(4), one O(5), one O(6), one O(7), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Pr(1), one Y(1), and one Si(2) atom. In the second O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Pr(1), one Y(1), and one Si(2) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Pr(1), one Y(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(2) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Y(1), and one Si(1) atom. In the sixth O site, O(3) is bonded in a 4-coordinate geometry to one Pr(1), two equivalent Y(1), and one Si(1) atom. In the seventh O site, O(4) is bonded in a 3-coordinate geometry to one Pr(1), one Y(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_PrYSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.673
_cell_length_b   5.443
_cell_length_c   13.981
_cell_angle_alpha   67.534
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   609.877
_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
  Pr  Pr0  1  0.809  0.474  0.772  1.0
  Pr  Pr1  1  0.309  0.526  0.728  1.0
  Pr  Pr2  1  0.191  0.526  0.228  1.0
  Pr  Pr3  1  0.691  0.474  0.272  1.0
  Y  Y4  1  0.604  0.174  0.592  1.0
  Y  Y5  1  0.104  0.826  0.908  1.0
  Y  Y6  1  0.396  0.826  0.408  1.0
  Y  Y7  1  0.896  0.174  0.092  1.0
  Si  Si8  1  0.247  0.257  0.021  1.0
  Si  Si9  1  0.747  0.743  0.479  1.0
  Si  Si10  1  0.753  0.743  0.979  1.0
  Si  Si11  1  0.253  0.257  0.521  1.0
  Si  Si12  1  0.506  0.038  0.179  1.0
  Si  Si13  1  0.006  0.962  0.321  1.0
  Si  Si14  1  0.494  0.962  0.821  1.0
  Si  Si15  1  0.994  0.038  0.679  1.0
  O  O16  1  0.422  0.208  0.069  1.0
  O  O17  1  0.922  0.792  0.431  1.0
  O  O18  1  0.578  0.792  0.931  1.0
  O  O19  1  0.078  0.208  0.569  1.0
  O  O20  1  0.157  0.977  0.039  1.0
  O  O21  1  0.657  0.023  0.461  1.0
  O  O22  1  0.843  0.023  0.961  1.0
  O  O23  1  0.343  0.977  0.539  1.0
  O  O24  1  0.136  0.411  0.078  1.0
  O  O25  1  0.636  0.589  0.422  1.0
  O  O26  1  0.864  0.589  0.922  1.0
  O  O27  1  0.364  0.411  0.578  1.0
  O  O28  1  0.250  0.473  0.903  1.0
  O  O29  1  0.750  0.527  0.597  1.0
  O  O30  1  0.750  0.527  0.097  1.0
  O  O31  1  0.250  0.473  0.403  1.0
  O  O32  1  0.489  0.195  0.259  1.0
  O  O33  1  0.989  0.805  0.241  1.0
  O  O34  1  0.511  0.805  0.741  1.0
  O  O35  1  0.011  0.195  0.759  1.0
  O  O36  1  0.423  0.748  0.239  1.0
  O  O37  1  0.923  0.252  0.261  1.0
  O  O38  1  0.577  0.252  0.761  1.0
  O  O39  1  0.077  0.748  0.739  1.0
  O  O40  1  0.684  0.961  0.167  1.0
  O  O41  1  0.184  0.039  0.333  1.0
  O  O42  1  0.316  0.039  0.833  1.0
  O  O43  1  0.816  0.961  0.667  1.0
[/CIF]
.