The crystal structure described by PrYSi2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(12), one O(13), one O(14), one O(2), and one O(8) atom. In the second Pr site, Pr(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(3), one O(4), one O(5), and one O(7) atom. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(13), one O(3), one O(8), and two equivalent O(12) atoms. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(2), one O(4), one O(5), and two equivalent O(7) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(5), and one O(9) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(6), and one O(7) atom. In the third Si site, Si(3) is bonded in a trigonal non-coplanar geometry to one O(10), one O(6), and one O(8) atom. In the fourth Si site, Si(4) is bonded in a tetrahedral geometry to one O(12), one O(13), one O(3), and one O(9) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Pr(1), one Y(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Pr(1), one Y(2), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Pr(2), one Y(1), and one Si(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Pr(2), one Y(2), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Pr(2), one Y(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Si(2) and one Si(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Pr(2), two equivalent Y(2), and one Si(2) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Pr(1), one Y(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Si(1) and one Si(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Pr(2), one Y(2), and one Si(3) atom. In the eleventh O site, O(11) is bonded in a trigonal non-coplanar geometry to one Pr(1), one Pr(2), and one Y(1) atom. In the twelfth O site, O(12) is bonded to one Pr(1), two equivalent Y(1), and one Si(4) atom to form distorted edge-sharing OPrY2Si tetrahedra. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Pr(1), one Y(1), and one Si(4) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Pr(1) and one Y(2) atom. is represented by the CIF file [CIF]
data_PrYSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.436
_cell_length_b   8.990
_cell_length_c   11.565
_cell_angle_alpha   89.077
_cell_angle_beta   95.286
_cell_angle_gamma   90.830
_symmetry_Int_Tables_number   1
_cell_volume   666.191
_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  0.754  0.596  0.273  1.0
  Pr  Pr1  1  0.246  0.404  0.727  1.0
  Pr  Pr2  1  0.309  0.831  0.780  1.0
  Pr  Pr3  1  0.691  0.169  0.220  1.0
  Y  Y4  1  0.711  0.605  0.615  1.0
  Y  Y5  1  0.289  0.395  0.385  1.0
  Y  Y6  1  0.225  0.892  0.118  1.0
  Y  Y7  1  0.775  0.108  0.882  1.0
  Si  Si8  1  0.479  0.896  0.425  1.0
  Si  Si9  1  0.688  0.826  0.043  1.0
  Si  Si10  1  0.984  0.615  0.940  1.0
  Si  Si11  1  0.312  0.174  0.957  1.0
  Si  Si12  1  0.834  0.322  0.486  1.0
  Si  Si13  1  0.166  0.678  0.514  1.0
  Si  Si14  1  0.521  0.104  0.575  1.0
  Si  Si15  1  0.016  0.385  0.060  1.0
  O  O16  1  0.350  0.235  0.559  1.0
  O  O17  1  0.463  0.226  0.858  1.0
  O  O18  1  0.033  0.719  0.621  1.0
  O  O19  1  0.580  0.899  0.921  1.0
  O  O20  1  0.447  0.992  0.306  1.0
  O  O21  1  0.967  0.281  0.379  1.0
  O  O22  1  0.783  0.664  0.006  1.0
  O  O23  1  0.864  0.955  0.085  1.0
  O  O24  1  0.966  0.552  0.811  1.0
  O  O25  1  0.733  0.157  0.518  1.0
  O  O26  1  0.172  0.736  0.963  1.0
  O  O27  1  0.511  0.371  0.249  1.0
  O  O28  1  0.343  0.549  0.548  1.0
  O  O29  1  0.828  0.264  0.037  1.0
  O  O30  1  0.553  0.008  0.694  1.0
  O  O31  1  0.657  0.451  0.452  1.0
  O  O32  1  0.537  0.774  0.142  1.0
  O  O33  1  0.941  0.400  0.604  1.0
  O  O34  1  0.136  0.045  0.915  1.0
  O  O35  1  0.489  0.629  0.751  1.0
  O  O36  1  0.998  0.207  0.768  1.0
  O  O37  1  0.217  0.336  0.994  1.0
  O  O38  1  0.650  0.765  0.441  1.0
  O  O39  1  0.034  0.448  0.189  1.0
  O  O40  1  0.267  0.843  0.482  1.0
  O  O41  1  0.059  0.600  0.396  1.0
  O  O42  1  0.420  0.101  0.079  1.0
  O  O43  1  0.002  0.793  0.232  1.0
[/CIF]
.
The crystal structure described by PrYSi2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(12), one O(13), one O(14), one O(2), and one O(8) atom. In the second Pr site, Pr(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(3), one O(4), one O(5), and one O(7) atom. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(13), one O(3), one O(8), and two equivalent O(12) atoms. In the second Y site, Y(2) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(2), one O(4), one O(5), and two equivalent O(7) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(5), and one O(9) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(6), and one O(7) atom. In the third Si site, Si(3) is bonded in a trigonal non-coplanar geometry to one O(10), one O(6), and one O(8) atom. In the fourth Si site, Si(4) is bonded in a tetrahedral geometry to one O(12), one O(13), one O(3), and one O(9) atom. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Pr(1), one Y(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Pr(1), one Y(2), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Pr(2), one Y(1), and one Si(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Pr(2), one Y(2), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Pr(2), one Y(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Si(2) and one Si(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Pr(2), two equivalent Y(2), and one Si(2) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Pr(1), one Y(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Si(1) and one Si(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Pr(2), one Y(2), and one Si(3) atom. In the eleventh O site, O(11) is bonded in a trigonal non-coplanar geometry to one Pr(1), one Pr(2), and one Y(1) atom. In the twelfth O site, O(12) is bonded to one Pr(1), two equivalent Y(1), and one Si(4) atom to form distorted edge-sharing OPrY2Si tetrahedra. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Pr(1), one Y(1), and one Si(4) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Pr(1) and one Y(2) atom. is represented by the CIF file [CIF]
data_PrYSi2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.436
_cell_length_b   8.990
_cell_length_c   11.565
_cell_angle_alpha   89.077
_cell_angle_beta   95.286
_cell_angle_gamma   90.830
_symmetry_Int_Tables_number   1
_cell_volume   666.191
_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  0.754  0.596  0.273  1.0
  Pr  Pr1  1  0.246  0.404  0.727  1.0
  Pr  Pr2  1  0.309  0.831  0.780  1.0
  Pr  Pr3  1  0.691  0.169  0.220  1.0
  Y  Y4  1  0.711  0.605  0.615  1.0
  Y  Y5  1  0.289  0.395  0.385  1.0
  Y  Y6  1  0.225  0.892  0.118  1.0
  Y  Y7  1  0.775  0.108  0.882  1.0
  Si  Si8  1  0.479  0.896  0.425  1.0
  Si  Si9  1  0.688  0.826  0.043  1.0
  Si  Si10  1  0.984  0.615  0.940  1.0
  Si  Si11  1  0.312  0.174  0.957  1.0
  Si  Si12  1  0.834  0.322  0.486  1.0
  Si  Si13  1  0.166  0.678  0.514  1.0
  Si  Si14  1  0.521  0.104  0.575  1.0
  Si  Si15  1  0.016  0.385  0.060  1.0
  O  O16  1  0.350  0.235  0.559  1.0
  O  O17  1  0.463  0.226  0.858  1.0
  O  O18  1  0.033  0.719  0.621  1.0
  O  O19  1  0.580  0.899  0.921  1.0
  O  O20  1  0.447  0.992  0.306  1.0
  O  O21  1  0.967  0.281  0.379  1.0
  O  O22  1  0.783  0.664  0.006  1.0
  O  O23  1  0.864  0.955  0.085  1.0
  O  O24  1  0.966  0.552  0.811  1.0
  O  O25  1  0.733  0.157  0.518  1.0
  O  O26  1  0.172  0.736  0.963  1.0
  O  O27  1  0.511  0.371  0.249  1.0
  O  O28  1  0.343  0.549  0.548  1.0
  O  O29  1  0.828  0.264  0.037  1.0
  O  O30  1  0.553  0.008  0.694  1.0
  O  O31  1  0.657  0.451  0.452  1.0
  O  O32  1  0.537  0.774  0.142  1.0
  O  O33  1  0.941  0.400  0.604  1.0
  O  O34  1  0.136  0.045  0.915  1.0
  O  O35  1  0.489  0.629  0.751  1.0
  O  O36  1  0.998  0.207  0.768  1.0
  O  O37  1  0.217  0.336  0.994  1.0
  O  O38  1  0.650  0.765  0.441  1.0
  O  O39  1  0.034  0.448  0.189  1.0
  O  O40  1  0.267  0.843  0.482  1.0
  O  O41  1  0.059  0.600  0.396  1.0
  O  O42  1  0.420  0.101  0.079  1.0
  O  O43  1  0.002  0.793  0.232  1.0
[/CIF]
.