The structure described by NaTaAl(PO4)3 crystallizes in the trigonal R3c space group. Na(1) is bonded in a distorted hexagonal planar geometry to three equivalent O(3) and three equivalent O(4) atoms. Ta(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form TaO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. Al(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form AlO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-33°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ta(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Ta(1), and one P(1) atom. is represented by the CIF card [CIF]
data_NaTaAl(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.550
_cell_length_b   8.550
_cell_length_c   8.902
_cell_angle_alpha   61.300
_cell_angle_beta   61.300
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   469.038
_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
  Al  Al0  1  0.354  0.354  0.939  1.0
  Al  Al1  1  0.854  0.854  0.439  1.0
  Na  Na2  1  0.494  0.494  0.517  1.0
  Na  Na3  1  0.994  0.994  0.017  1.0
  O  O4  1  0.273  0.140  0.078  1.0
  O  O5  1  0.508  0.273  0.078  1.0
  O  O6  1  0.140  0.508  0.078  1.0
  O  O7  1  0.640  0.773  0.578  1.0
  O  O8  1  0.008  0.640  0.578  1.0
  O  O9  1  0.773  0.008  0.578  1.0
  O  O10  1  0.721  0.867  0.917  1.0
  O  O11  1  0.495  0.721  0.917  1.0
  O  O12  1  0.867  0.495  0.917  1.0
  O  O13  1  0.367  0.221  0.417  1.0
  O  O14  1  0.995  0.367  0.417  1.0
  O  O15  1  0.221  0.995  0.417  1.0
  O  O16  1  0.567  0.221  0.774  1.0
  O  O17  1  0.438  0.567  0.774  1.0
  O  O18  1  0.221  0.438  0.774  1.0
  O  O19  1  0.721  0.067  0.274  1.0
  O  O20  1  0.938  0.721  0.274  1.0
  O  O21  1  0.067  0.938  0.274  1.0
  O  O22  1  0.419  0.786  0.229  1.0
  O  O23  1  0.565  0.419  0.229  1.0
  O  O24  1  0.786  0.565  0.229  1.0
  O  O25  1  0.286  0.919  0.729  1.0
  O  O26  1  0.065  0.286  0.729  1.0
  O  O27  1  0.919  0.065  0.729  1.0
  P  P28  1  0.239  0.973  0.244  1.0
  P  P29  1  0.544  0.239  0.244  1.0
  P  P30  1  0.973  0.544  0.244  1.0
  P  P31  1  0.473  0.739  0.744  1.0
  P  P32  1  0.044  0.473  0.744  1.0
  P  P33  1  0.739  0.044  0.744  1.0
  Ta  Ta34  1  0.644  0.644  0.068  1.0
  Ta  Ta35  1  0.144  0.144  0.568  1.0
[/CIF]
.
The structure described by NaTaAl(PO4)3 crystallizes in the trigonal R3c space group. Na(1) is bonded in a distorted hexagonal planar geometry to three equivalent O(3) and three equivalent O(4) atoms. Ta(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form TaO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. Al(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form AlO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ta(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 25-33°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ta(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Ta(1), and one P(1) atom. is represented by the CIF card [CIF]
data_NaTaAl(PO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.550
_cell_length_b   8.550
_cell_length_c   8.902
_cell_angle_alpha   61.300
_cell_angle_beta   61.300
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   469.038
_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
  Al  Al0  1  0.354  0.354  0.939  1.0
  Al  Al1  1  0.854  0.854  0.439  1.0
  Na  Na2  1  0.494  0.494  0.517  1.0
  Na  Na3  1  0.994  0.994  0.017  1.0
  O  O4  1  0.273  0.140  0.078  1.0
  O  O5  1  0.508  0.273  0.078  1.0
  O  O6  1  0.140  0.508  0.078  1.0
  O  O7  1  0.640  0.773  0.578  1.0
  O  O8  1  0.008  0.640  0.578  1.0
  O  O9  1  0.773  0.008  0.578  1.0
  O  O10  1  0.721  0.867  0.917  1.0
  O  O11  1  0.495  0.721  0.917  1.0
  O  O12  1  0.867  0.495  0.917  1.0
  O  O13  1  0.367  0.221  0.417  1.0
  O  O14  1  0.995  0.367  0.417  1.0
  O  O15  1  0.221  0.995  0.417  1.0
  O  O16  1  0.567  0.221  0.774  1.0
  O  O17  1  0.438  0.567  0.774  1.0
  O  O18  1  0.221  0.438  0.774  1.0
  O  O19  1  0.721  0.067  0.274  1.0
  O  O20  1  0.938  0.721  0.274  1.0
  O  O21  1  0.067  0.938  0.274  1.0
  O  O22  1  0.419  0.786  0.229  1.0
  O  O23  1  0.565  0.419  0.229  1.0
  O  O24  1  0.786  0.565  0.229  1.0
  O  O25  1  0.286  0.919  0.729  1.0
  O  O26  1  0.065  0.286  0.729  1.0
  O  O27  1  0.919  0.065  0.729  1.0
  P  P28  1  0.239  0.973  0.244  1.0
  P  P29  1  0.544  0.239  0.244  1.0
  P  P30  1  0.973  0.544  0.244  1.0
  P  P31  1  0.473  0.739  0.744  1.0
  P  P32  1  0.044  0.473  0.744  1.0
  P  P33  1  0.739  0.044  0.744  1.0
  Ta  Ta34  1  0.644  0.644  0.068  1.0
  Ta  Ta35  1  0.144  0.144  0.568  1.0
[/CIF]
.