The crystal structure described by Na4YHfSi2PO12 crystallizes in the monoclinic Cc space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), one O(9), and two equivalent O(5) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(2), one O(4), one O(7), and one O(8) atom. In the fourth Na site, Na(4) is bonded in a distorted hexagonal planar geometry to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom. Y(1) is bonded to one O(1), one O(2), one O(3), one O(7), one O(8), and one O(9) atom to form YO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. Hf(1) is bonded to one O(10), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form HfO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Hf(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-39°. In the second Si site, Si(2) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Hf(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-38°. P(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Hf(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-36°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Y(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(3), one Y(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one Y(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Na(3), one Hf(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Na(1), one Hf(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Hf(1), and one P(1) atom. In the seventh O site, O(7) is bonded to one Na(1), one Na(3), one Na(4), one Y(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing ONa3YSi trigonal bipyramids. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), one Y(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), one Y(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(4), one Hf(1), and one P(1) atom. In the eleventh O site, O(11) is bonded to one Na(1), one Na(2), one Na(4), one Hf(1), and one Si(1) atom to form distorted ONa3HfSi trigonal bipyramids that share corners with two equivalent O(7)Na3YSi trigonal bipyramids and  a faceface with one O(12)Na3HfSi trigonal bipyramid. In the twelfth O site, O(12) is bonded to one Na(2), one Na(3), one Na(4), one Hf(1), and one Si(2) atom to form distorted ONa3HfSi trigonal bipyramids that share  a cornercorner with one O(7)Na3YSi trigonal bipyramid,  an edgeedge with one O(7)Na3YSi trigonal bipyramid, and  a faceface with one O(11)Na3HfSi trigonal bipyramid. is represented by the CIF card [CIF]
data_Na4YHfSi2PO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.324
_cell_length_b   9.337
_cell_length_c   9.337
_cell_angle_alpha   60.283
_cell_angle_beta   60.136
_cell_angle_gamma   60.136
_symmetry_Int_Tables_number   1
_cell_volume   577.165
_cell_formula_units_Z   2
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
  Hf  Hf0  1  0.651  0.648  0.648  1.0
  Hf  Hf1  1  0.151  0.148  0.148  1.0
  Na  Na2  1  0.613  0.245  0.896  1.0
  Na  Na3  1  0.244  0.876  0.615  1.0
  Na  Na4  1  0.886  0.624  0.238  1.0
  Na  Na5  1  0.744  0.115  0.376  1.0
  Na  Na6  1  0.113  0.396  0.745  1.0
  Na  Na7  1  0.386  0.738  0.124  1.0
  Na  Na8  1  0.493  0.510  0.492  1.0
  Na  Na9  1  0.993  0.992  0.010  1.0
  O  O10  1  0.109  0.281  0.527  1.0
  O  O11  1  0.279  0.529  0.117  1.0
  O  O12  1  0.526  0.113  0.290  1.0
  O  O13  1  0.779  0.617  0.029  1.0
  O  O14  1  0.609  0.027  0.781  1.0
  O  O15  1  0.026  0.790  0.613  1.0
  O  O16  1  0.867  0.724  0.490  1.0
  O  O17  1  0.724  0.489  0.867  1.0
  O  O18  1  0.489  0.874  0.726  1.0
  O  O19  1  0.224  0.367  0.989  1.0
  O  O20  1  0.367  0.990  0.224  1.0
  O  O21  1  0.989  0.226  0.374  1.0
  O  O22  1  0.226  0.589  0.426  1.0
  O  O23  1  0.595  0.414  0.231  1.0
  O  O24  1  0.413  0.212  0.604  1.0
  O  O25  1  0.095  0.731  0.914  1.0
  O  O26  1  0.726  0.926  0.089  1.0
  O  O27  1  0.913  0.104  0.712  1.0
  O  O28  1  0.784  0.425  0.554  1.0
  O  O29  1  0.435  0.558  0.771  1.0
  O  O30  1  0.563  0.769  0.431  1.0
  O  O31  1  0.935  0.271  0.058  1.0
  O  O32  1  0.284  0.054  0.925  1.0
  O  O33  1  0.063  0.931  0.269  1.0
  P  P34  1  0.950  0.257  0.542  1.0
  P  P35  1  0.450  0.042  0.757  1.0
  Si  Si36  1  0.256  0.547  0.947  1.0
  Si  Si37  1  0.547  0.949  0.257  1.0
  Si  Si38  1  0.756  0.447  0.047  1.0
  Si  Si39  1  0.047  0.757  0.449  1.0
  Y  Y40  1  0.350  0.353  0.345  1.0
  Y  Y41  1  0.850  0.845  0.853  1.0
[/CIF]
.
The crystal structure described by Na4YHfSi2PO12 crystallizes in the monoclinic Cc space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), one O(9), and two equivalent O(5) atoms. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(2), one O(4), one O(7), and one O(8) atom. In the fourth Na site, Na(4) is bonded in a distorted hexagonal planar geometry to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom. Y(1) is bonded to one O(1), one O(2), one O(3), one O(7), one O(8), and one O(9) atom to form YO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. Hf(1) is bonded to one O(10), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form HfO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Hf(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-39°. In the second Si site, Si(2) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Hf(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-38°. P(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Hf(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-36°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Y(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(3), one Y(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Na(2), one Y(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Na(3), one Hf(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to two equivalent Na(1), one Hf(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Hf(1), and one P(1) atom. In the seventh O site, O(7) is bonded to one Na(1), one Na(3), one Na(4), one Y(1), and one Si(2) atom to form a mixture of distorted edge and corner-sharing ONa3YSi trigonal bipyramids. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), one Y(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), one Y(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(4), one Hf(1), and one P(1) atom. In the eleventh O site, O(11) is bonded to one Na(1), one Na(2), one Na(4), one Hf(1), and one Si(1) atom to form distorted ONa3HfSi trigonal bipyramids that share corners with two equivalent O(7)Na3YSi trigonal bipyramids and  a faceface with one O(12)Na3HfSi trigonal bipyramid. In the twelfth O site, O(12) is bonded to one Na(2), one Na(3), one Na(4), one Hf(1), and one Si(2) atom to form distorted ONa3HfSi trigonal bipyramids that share  a cornercorner with one O(7)Na3YSi trigonal bipyramid,  an edgeedge with one O(7)Na3YSi trigonal bipyramid, and  a faceface with one O(11)Na3HfSi trigonal bipyramid. is represented by the CIF card [CIF]
data_Na4YHfSi2PO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.324
_cell_length_b   9.337
_cell_length_c   9.337
_cell_angle_alpha   60.283
_cell_angle_beta   60.136
_cell_angle_gamma   60.136
_symmetry_Int_Tables_number   1
_cell_volume   577.165
_cell_formula_units_Z   2
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
  Hf  Hf0  1  0.651  0.648  0.648  1.0
  Hf  Hf1  1  0.151  0.148  0.148  1.0
  Na  Na2  1  0.613  0.245  0.896  1.0
  Na  Na3  1  0.244  0.876  0.615  1.0
  Na  Na4  1  0.886  0.624  0.238  1.0
  Na  Na5  1  0.744  0.115  0.376  1.0
  Na  Na6  1  0.113  0.396  0.745  1.0
  Na  Na7  1  0.386  0.738  0.124  1.0
  Na  Na8  1  0.493  0.510  0.492  1.0
  Na  Na9  1  0.993  0.992  0.010  1.0
  O  O10  1  0.109  0.281  0.527  1.0
  O  O11  1  0.279  0.529  0.117  1.0
  O  O12  1  0.526  0.113  0.290  1.0
  O  O13  1  0.779  0.617  0.029  1.0
  O  O14  1  0.609  0.027  0.781  1.0
  O  O15  1  0.026  0.790  0.613  1.0
  O  O16  1  0.867  0.724  0.490  1.0
  O  O17  1  0.724  0.489  0.867  1.0
  O  O18  1  0.489  0.874  0.726  1.0
  O  O19  1  0.224  0.367  0.989  1.0
  O  O20  1  0.367  0.990  0.224  1.0
  O  O21  1  0.989  0.226  0.374  1.0
  O  O22  1  0.226  0.589  0.426  1.0
  O  O23  1  0.595  0.414  0.231  1.0
  O  O24  1  0.413  0.212  0.604  1.0
  O  O25  1  0.095  0.731  0.914  1.0
  O  O26  1  0.726  0.926  0.089  1.0
  O  O27  1  0.913  0.104  0.712  1.0
  O  O28  1  0.784  0.425  0.554  1.0
  O  O29  1  0.435  0.558  0.771  1.0
  O  O30  1  0.563  0.769  0.431  1.0
  O  O31  1  0.935  0.271  0.058  1.0
  O  O32  1  0.284  0.054  0.925  1.0
  O  O33  1  0.063  0.931  0.269  1.0
  P  P34  1  0.950  0.257  0.542  1.0
  P  P35  1  0.450  0.042  0.757  1.0
  Si  Si36  1  0.256  0.547  0.947  1.0
  Si  Si37  1  0.547  0.949  0.257  1.0
  Si  Si38  1  0.756  0.447  0.047  1.0
  Si  Si39  1  0.047  0.757  0.449  1.0
  Y  Y40  1  0.350  0.353  0.345  1.0
  Y  Y41  1  0.850  0.845  0.853  1.0
[/CIF]
.