The compound described by NaYbP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(7) atoms. Yb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form YbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Yb(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 15-52°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Yb(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-50°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Yb(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Yb(1), and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Yb(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Yb(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Yb(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Yb(1), and one P(1) atom. is represented by the CIF card [CIF]
data_NaYbP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.494
_cell_length_b   9.297
_cell_length_c   14.274
_cell_angle_alpha   63.898
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   654.777
_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
  Na  Na0  1  0.727  0.557  0.306  1.0
  Na  Na1  1  0.273  0.443  0.694  1.0
  Na  Na2  1  0.227  0.443  0.194  1.0
  Na  Na3  1  0.773  0.557  0.806  1.0
  Yb  Yb4  1  0.261  0.253  0.478  1.0
  Yb  Yb5  1  0.761  0.747  0.022  1.0
  Yb  Yb6  1  0.739  0.747  0.522  1.0
  Yb  Yb7  1  0.239  0.253  0.978  1.0
  P  P8  1  0.751  0.184  0.344  1.0
  P  P9  1  0.216  0.687  0.380  1.0
  P  P10  1  0.716  0.313  0.120  1.0
  P  P11  1  0.284  0.687  0.880  1.0
  P  P12  1  0.784  0.313  0.620  1.0
  P  P13  1  0.249  0.816  0.656  1.0
  P  P14  1  0.251  0.816  0.156  1.0
  P  P15  1  0.749  0.184  0.844  1.0
  O  O16  1  0.489  0.728  0.662  1.0
  O  O17  1  0.294  0.530  0.378  1.0
  O  O18  1  0.443  0.310  0.100  1.0
  O  O19  1  0.706  0.470  0.622  1.0
  O  O20  1  0.259  0.985  0.071  1.0
  O  O21  1  0.721  0.170  0.735  1.0
  O  O22  1  0.872  0.280  0.043  1.0
  O  O23  1  0.989  0.272  0.838  1.0
  O  O24  1  0.279  0.830  0.265  1.0
  O  O25  1  0.741  0.015  0.929  1.0
  O  O26  1  0.464  0.713  0.149  1.0
  O  O27  1  0.036  0.713  0.649  1.0
  O  O28  1  0.536  0.287  0.851  1.0
  O  O29  1  0.943  0.690  0.400  1.0
  O  O30  1  0.759  0.015  0.429  1.0
  O  O31  1  0.011  0.728  0.162  1.0
  O  O32  1  0.241  0.985  0.571  1.0
  O  O33  1  0.779  0.170  0.235  1.0
  O  O34  1  0.628  0.280  0.543  1.0
  O  O35  1  0.221  0.830  0.765  1.0
  O  O36  1  0.206  0.530  0.878  1.0
  O  O37  1  0.511  0.272  0.338  1.0
  O  O38  1  0.964  0.287  0.351  1.0
  O  O39  1  0.794  0.470  0.122  1.0
  O  O40  1  0.128  0.720  0.957  1.0
  O  O41  1  0.372  0.720  0.457  1.0
  O  O42  1  0.057  0.310  0.600  1.0
  O  O43  1  0.557  0.690  0.900  1.0
[/CIF]
.
The compound described by NaYbP2O7 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(7) atoms. Yb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form YbO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Yb(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 15-52°. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Yb(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-50°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Yb(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Yb(1), and one P(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(1), one Yb(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted linear geometry to one Yb(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Yb(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Yb(1), and one P(1) atom. is represented by the CIF card [CIF]
data_NaYbP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.494
_cell_length_b   9.297
_cell_length_c   14.274
_cell_angle_alpha   63.898
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   654.777
_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
  Na  Na0  1  0.727  0.557  0.306  1.0
  Na  Na1  1  0.273  0.443  0.694  1.0
  Na  Na2  1  0.227  0.443  0.194  1.0
  Na  Na3  1  0.773  0.557  0.806  1.0
  Yb  Yb4  1  0.261  0.253  0.478  1.0
  Yb  Yb5  1  0.761  0.747  0.022  1.0
  Yb  Yb6  1  0.739  0.747  0.522  1.0
  Yb  Yb7  1  0.239  0.253  0.978  1.0
  P  P8  1  0.751  0.184  0.344  1.0
  P  P9  1  0.216  0.687  0.380  1.0
  P  P10  1  0.716  0.313  0.120  1.0
  P  P11  1  0.284  0.687  0.880  1.0
  P  P12  1  0.784  0.313  0.620  1.0
  P  P13  1  0.249  0.816  0.656  1.0
  P  P14  1  0.251  0.816  0.156  1.0
  P  P15  1  0.749  0.184  0.844  1.0
  O  O16  1  0.489  0.728  0.662  1.0
  O  O17  1  0.294  0.530  0.378  1.0
  O  O18  1  0.443  0.310  0.100  1.0
  O  O19  1  0.706  0.470  0.622  1.0
  O  O20  1  0.259  0.985  0.071  1.0
  O  O21  1  0.721  0.170  0.735  1.0
  O  O22  1  0.872  0.280  0.043  1.0
  O  O23  1  0.989  0.272  0.838  1.0
  O  O24  1  0.279  0.830  0.265  1.0
  O  O25  1  0.741  0.015  0.929  1.0
  O  O26  1  0.464  0.713  0.149  1.0
  O  O27  1  0.036  0.713  0.649  1.0
  O  O28  1  0.536  0.287  0.851  1.0
  O  O29  1  0.943  0.690  0.400  1.0
  O  O30  1  0.759  0.015  0.429  1.0
  O  O31  1  0.011  0.728  0.162  1.0
  O  O32  1  0.241  0.985  0.571  1.0
  O  O33  1  0.779  0.170  0.235  1.0
  O  O34  1  0.628  0.280  0.543  1.0
  O  O35  1  0.221  0.830  0.765  1.0
  O  O36  1  0.206  0.530  0.878  1.0
  O  O37  1  0.511  0.272  0.338  1.0
  O  O38  1  0.964  0.287  0.351  1.0
  O  O39  1  0.794  0.470  0.122  1.0
  O  O40  1  0.128  0.720  0.957  1.0
  O  O41  1  0.372  0.720  0.457  1.0
  O  O42  1  0.057  0.310  0.600  1.0
  O  O43  1  0.557  0.690  0.900  1.0
[/CIF]
.