The material described by Na3CaNbSi(PO6)2 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the monoclinic Cc space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(12), one O(2), one O(5), and one O(6) atom. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(2), one O(7), and one O(9) atom. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(11), one O(5), one O(6), one O(7), one O(8), and two equivalent O(4) atoms. Ca(1) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one O(9) atom to form CaO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. Nb(1) is bonded to one O(10), one O(12), one O(2), one O(3), one O(6), and one O(7) atom to form NbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. Si(1) is bonded to one O(1), one O(10), one O(6), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-43°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(12), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-46°. In the second P site, P(2) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-47°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Ca(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Nb(1), and one P(2) atom. In the third O site, O(3) is bonded in a linear geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(3), one Ca(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ca(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Nb(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Nb(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(3), one Ca(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Ca(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Nb(1), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Ca(1), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one P(1) atom. is represented by the CIF card [CIF]
data_Na3CaNbSi(PO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.089
_cell_length_b   9.178
_cell_length_c   9.178
_cell_angle_alpha   60.630
_cell_angle_beta   60.952
_cell_angle_gamma   60.952
_symmetry_Int_Tables_number   1
_cell_volume   551.674
_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
  Ca  Ca0  1  0.643  0.148  0.642  1.0
  Ca  Ca1  1  0.143  0.642  0.148  1.0
  Na  Na2  1  0.521  0.023  0.469  1.0
  Na  Na3  1  0.021  0.469  0.023  1.0
  Na  Na4  1  0.268  0.399  0.581  1.0
  Na  Na5  1  0.768  0.581  0.399  1.0
  Na  Na6  1  0.053  0.890  0.748  1.0
  Na  Na7  1  0.553  0.748  0.890  1.0
  Nb  Nb8  1  0.854  0.347  0.860  1.0
  Nb  Nb9  1  0.354  0.860  0.347  1.0
  O  O10  1  0.560  0.287  0.398  1.0
  O  O11  1  0.967  0.558  0.731  1.0
  O  O12  1  0.467  0.731  0.558  1.0
  O  O13  1  0.060  0.398  0.287  1.0
  O  O14  1  0.275  0.996  0.137  1.0
  O  O15  1  0.177  0.908  0.984  1.0
  O  O16  1  0.677  0.984  0.908  1.0
  O  O17  1  0.775  0.137  0.996  1.0
  O  O18  1  0.775  0.867  0.613  1.0
  O  O19  1  0.743  0.449  0.055  1.0
  O  O20  1  0.243  0.055  0.449  1.0
  O  O21  1  0.275  0.613  0.867  1.0
  O  O22  1  0.128  0.779  0.506  1.0
  O  O23  1  0.405  0.538  0.152  1.0
  O  O24  1  0.905  0.152  0.538  1.0
  O  O25  1  0.628  0.506  0.779  1.0
  O  O26  1  0.977  0.680  0.414  1.0
  O  O27  1  0.512  0.644  0.286  1.0
  O  O28  1  0.012  0.286  0.644  1.0
  O  O29  1  0.477  0.414  0.680  1.0
  O  O30  1  0.381  0.086  0.796  1.0
  O  O31  1  0.064  0.228  0.959  1.0
  O  O32  1  0.564  0.959  0.228  1.0
  O  O33  1  0.881  0.796  0.086  1.0
  P  P34  1  0.226  0.052  0.964  1.0
  P  P35  1  0.726  0.964  0.052  1.0
  P  P36  1  0.954  0.729  0.560  1.0
  P  P37  1  0.454  0.560  0.729  1.0
  Si  Si38  1  0.556  0.465  0.231  1.0
  Si  Si39  1  0.056  0.231  0.465  1.0
[/CIF]
.
The material described by Na3CaNbSi(PO6)2 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the monoclinic Cc space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(12), one O(2), one O(5), and one O(6) atom. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(2), one O(7), and one O(9) atom. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(11), one O(5), one O(6), one O(7), one O(8), and two equivalent O(4) atoms. Ca(1) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one O(9) atom to form CaO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. Nb(1) is bonded to one O(10), one O(12), one O(2), one O(3), one O(6), and one O(7) atom to form NbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. Si(1) is bonded to one O(1), one O(10), one O(6), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-43°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(11), one O(12), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-46°. In the second P site, P(2) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-47°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Ca(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Nb(1), and one P(2) atom. In the third O site, O(3) is bonded in a linear geometry to one Nb(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(3), one Ca(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ca(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Nb(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Nb(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(3), one Ca(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Ca(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Nb(1), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Ca(1), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one P(1) atom. is represented by the CIF card [CIF]
data_Na3CaNbSi(PO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.089
_cell_length_b   9.178
_cell_length_c   9.178
_cell_angle_alpha   60.630
_cell_angle_beta   60.952
_cell_angle_gamma   60.952
_symmetry_Int_Tables_number   1
_cell_volume   551.674
_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
  Ca  Ca0  1  0.643  0.148  0.642  1.0
  Ca  Ca1  1  0.143  0.642  0.148  1.0
  Na  Na2  1  0.521  0.023  0.469  1.0
  Na  Na3  1  0.021  0.469  0.023  1.0
  Na  Na4  1  0.268  0.399  0.581  1.0
  Na  Na5  1  0.768  0.581  0.399  1.0
  Na  Na6  1  0.053  0.890  0.748  1.0
  Na  Na7  1  0.553  0.748  0.890  1.0
  Nb  Nb8  1  0.854  0.347  0.860  1.0
  Nb  Nb9  1  0.354  0.860  0.347  1.0
  O  O10  1  0.560  0.287  0.398  1.0
  O  O11  1  0.967  0.558  0.731  1.0
  O  O12  1  0.467  0.731  0.558  1.0
  O  O13  1  0.060  0.398  0.287  1.0
  O  O14  1  0.275  0.996  0.137  1.0
  O  O15  1  0.177  0.908  0.984  1.0
  O  O16  1  0.677  0.984  0.908  1.0
  O  O17  1  0.775  0.137  0.996  1.0
  O  O18  1  0.775  0.867  0.613  1.0
  O  O19  1  0.743  0.449  0.055  1.0
  O  O20  1  0.243  0.055  0.449  1.0
  O  O21  1  0.275  0.613  0.867  1.0
  O  O22  1  0.128  0.779  0.506  1.0
  O  O23  1  0.405  0.538  0.152  1.0
  O  O24  1  0.905  0.152  0.538  1.0
  O  O25  1  0.628  0.506  0.779  1.0
  O  O26  1  0.977  0.680  0.414  1.0
  O  O27  1  0.512  0.644  0.286  1.0
  O  O28  1  0.012  0.286  0.644  1.0
  O  O29  1  0.477  0.414  0.680  1.0
  O  O30  1  0.381  0.086  0.796  1.0
  O  O31  1  0.064  0.228  0.959  1.0
  O  O32  1  0.564  0.959  0.228  1.0
  O  O33  1  0.881  0.796  0.086  1.0
  P  P34  1  0.226  0.052  0.964  1.0
  P  P35  1  0.726  0.964  0.052  1.0
  P  P36  1  0.954  0.729  0.560  1.0
  P  P37  1  0.454  0.560  0.729  1.0
  Si  Si38  1  0.556  0.465  0.231  1.0
  Si  Si39  1  0.056  0.231  0.465  1.0
[/CIF]
.