The structure described by NaNb2Si2PO12 crystallizes in the monoclinic Cc space group. Na(1) 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. There are two inequivalent Nb sites. In the first Nb site, Nb(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 NbO6 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. In the second Nb site, Nb(2) 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 NbO6 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(1), one O(10), one O(6), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-33°. In the second Si site, Si(2) 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 Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. P(1) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-32°. There are twelve inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(2) and one Si(1) atom. In the second O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one P(1) atom. In the third O site, O(8) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one Si(2) atom. In the fourth O site, O(9) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one Si(1) atom. In the fifth O site, O(10) is bonded in a 3-coordinate geometry to one Na(1), one Nb(2), and one Si(1) atom. In the sixth O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Nb(2), and one Si(2) atom. In the seventh O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Nb(2), and one P(1) atom. In the eighth O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(1) atom. In the ninth O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(2) atom. In the tenth O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the eleventh O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the twelfth O site, O(5) is bonded in a bent 150 degrees geometry to one Nb(2) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaNb2Si2PO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.877
_cell_length_b   8.877
_cell_length_c   9.212
_cell_angle_alpha   90.220
_cell_angle_beta   118.620
_cell_angle_gamma   119.931
_symmetry_Int_Tables_number   1
_cell_volume   523.387
_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
  Na  Na0  1  0.999  0.501  0.500  1.0
  Na  Na1  1  0.999  0.001  0.000  1.0
  Nb  Nb2  1  0.290  0.642  0.935  1.0
  Nb  Nb3  1  0.293  0.145  0.435  1.0
  Nb  Nb4  1  0.705  0.347  0.066  1.0
  Nb  Nb5  1  0.719  0.860  0.566  1.0
  O  O6  1  0.356  0.497  0.079  1.0
  O  O7  1  0.579  0.859  0.078  1.0
  O  O8  1  0.218  0.724  0.086  1.0
  O  O9  1  0.219  0.999  0.578  1.0
  O  O10  1  0.582  0.223  0.579  1.0
  O  O11  1  0.362  0.368  0.586  1.0
  O  O12  1  0.638  0.507  0.914  1.0
  O  O13  1  0.417  0.141  0.921  1.0
  O  O14  1  0.781  0.281  0.921  1.0
  O  O15  1  0.780  0.004  0.421  1.0
  O  O16  1  0.407  0.776  0.414  1.0
  O  O17  1  0.640  0.641  0.421  1.0
  O  O18  1  0.350  0.561  0.770  1.0
  O  O19  1  0.208  0.777  0.773  1.0
  O  O20  1  0.995  0.428  0.772  1.0
  O  O21  1  0.996  0.066  0.273  1.0
  O  O22  1  0.209  0.920  0.270  1.0
  O  O23  1  0.344  0.278  0.272  1.0
  O  O24  1  0.660  0.440  0.228  1.0
  O  O25  1  0.796  0.223  0.229  1.0
  O  O26  1  0.016  0.582  0.227  1.0
  O  O27  1  0.006  0.934  0.729  1.0
  O  O28  1  0.787  0.067  0.728  1.0
  O  O29  1  0.646  0.712  0.727  1.0
  P  P30  1  0.214  0.749  0.251  1.0
  P  P31  1  0.502  0.537  0.751  1.0
  Si  Si32  1  0.500  0.463  0.250  1.0
  Si  Si33  1  0.788  0.036  0.249  1.0
  Si  Si34  1  0.212  0.960  0.749  1.0
  Si  Si35  1  0.787  0.250  0.750  1.0
[/CIF]
.
The structure described by NaNb2Si2PO12 crystallizes in the monoclinic Cc space group. Na(1) 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. There are two inequivalent Nb sites. In the first Nb site, Nb(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 NbO6 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. In the second Nb site, Nb(2) 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 NbO6 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(1), one O(10), one O(6), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-33°. In the second Si site, Si(2) 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 Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-34°. P(1) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-32°. There are twelve inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Nb(2) and one Si(1) atom. In the second O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one P(1) atom. In the third O site, O(8) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one Si(2) atom. In the fourth O site, O(9) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one Si(1) atom. In the fifth O site, O(10) is bonded in a 3-coordinate geometry to one Na(1), one Nb(2), and one Si(1) atom. In the sixth O site, O(11) is bonded in a 3-coordinate geometry to one Na(1), one Nb(2), and one Si(2) atom. In the seventh O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Nb(2), and one P(1) atom. In the eighth O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(1) atom. In the ninth O site, O(2) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(2) atom. In the tenth O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(1) atom. In the eleventh O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one P(1) atom. In the twelfth O site, O(5) is bonded in a bent 150 degrees geometry to one Nb(2) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaNb2Si2PO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.877
_cell_length_b   8.877
_cell_length_c   9.212
_cell_angle_alpha   90.220
_cell_angle_beta   118.620
_cell_angle_gamma   119.931
_symmetry_Int_Tables_number   1
_cell_volume   523.387
_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
  Na  Na0  1  0.999  0.501  0.500  1.0
  Na  Na1  1  0.999  0.001  0.000  1.0
  Nb  Nb2  1  0.290  0.642  0.935  1.0
  Nb  Nb3  1  0.293  0.145  0.435  1.0
  Nb  Nb4  1  0.705  0.347  0.066  1.0
  Nb  Nb5  1  0.719  0.860  0.566  1.0
  O  O6  1  0.356  0.497  0.079  1.0
  O  O7  1  0.579  0.859  0.078  1.0
  O  O8  1  0.218  0.724  0.086  1.0
  O  O9  1  0.219  0.999  0.578  1.0
  O  O10  1  0.582  0.223  0.579  1.0
  O  O11  1  0.362  0.368  0.586  1.0
  O  O12  1  0.638  0.507  0.914  1.0
  O  O13  1  0.417  0.141  0.921  1.0
  O  O14  1  0.781  0.281  0.921  1.0
  O  O15  1  0.780  0.004  0.421  1.0
  O  O16  1  0.407  0.776  0.414  1.0
  O  O17  1  0.640  0.641  0.421  1.0
  O  O18  1  0.350  0.561  0.770  1.0
  O  O19  1  0.208  0.777  0.773  1.0
  O  O20  1  0.995  0.428  0.772  1.0
  O  O21  1  0.996  0.066  0.273  1.0
  O  O22  1  0.209  0.920  0.270  1.0
  O  O23  1  0.344  0.278  0.272  1.0
  O  O24  1  0.660  0.440  0.228  1.0
  O  O25  1  0.796  0.223  0.229  1.0
  O  O26  1  0.016  0.582  0.227  1.0
  O  O27  1  0.006  0.934  0.729  1.0
  O  O28  1  0.787  0.067  0.728  1.0
  O  O29  1  0.646  0.712  0.727  1.0
  P  P30  1  0.214  0.749  0.251  1.0
  P  P31  1  0.502  0.537  0.751  1.0
  Si  Si32  1  0.500  0.463  0.250  1.0
  Si  Si33  1  0.788  0.036  0.249  1.0
  Si  Si34  1  0.212  0.960  0.749  1.0
  Si  Si35  1  0.787  0.250  0.750  1.0
[/CIF]
.