The compound described by Na4NbGa(SiO4)3 crystallizes in the trigonal R3c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to three equivalent O(3) and three equivalent O(4) atoms. Nb(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form NbO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra. Ga(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form GaO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Ga(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. There are four inequivalent O sites. In the first O site, O(3) is bonded to one Na(2), two equivalent Na(1), one Ga(1), and one Si(1) atom to form distorted ONa3GaSi trigonal bipyramids that share corners with six equivalent O(4)Na3NbSi trigonal bipyramids,  an edgeedge with one O(4)Na3NbSi trigonal bipyramid, and faces with two equivalent O(3)Na3GaSi trigonal bipyramids. In the second O site, O(4) is bonded to one Na(2), two equivalent Na(1), one Nb(1), and one Si(1) atom to form distorted ONa3NbSi trigonal bipyramids that share corners with six equivalent O(3)Na3GaSi trigonal bipyramids,  an edgeedge with one O(3)Na3GaSi trigonal bipyramid, and faces with two equivalent O(4)Na3NbSi trigonal bipyramids. In the third O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1), one Ga(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(1), one Nb(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Na4NbGa(SiO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.061
_cell_length_b   9.061
_cell_length_c   9.063
_cell_angle_alpha   60.006
_cell_angle_beta   60.006
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   526.198
_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
  Ga  Ga0  1  0.351  0.351  0.947  1.0
  Ga  Ga1  1  0.851  0.851  0.447  1.0
  Na  Na2  1  0.238  0.621  0.256  1.0
  Na  Na3  1  0.885  0.238  0.256  1.0
  Na  Na4  1  0.621  0.885  0.256  1.0
  Na  Na5  1  0.121  0.738  0.756  1.0
  Na  Na6  1  0.385  0.121  0.756  1.0
  Na  Na7  1  0.738  0.385  0.756  1.0
  Na  Na8  1  0.495  0.495  0.514  1.0
  Na  Na9  1  0.995  0.995  0.014  1.0
  Nb  Nb10  1  0.647  0.647  0.060  1.0
  Nb  Nb11  1  0.147  0.147  0.560  1.0
  O  O12  1  0.274  0.141  0.069  1.0
  O  O13  1  0.516  0.274  0.069  1.0
  O  O14  1  0.141  0.516  0.069  1.0
  O  O15  1  0.641  0.774  0.569  1.0
  O  O16  1  0.016  0.641  0.569  1.0
  O  O17  1  0.774  0.016  0.569  1.0
  O  O18  1  0.727  0.858  0.923  1.0
  O  O19  1  0.492  0.727  0.923  1.0
  O  O20  1  0.858  0.492  0.923  1.0
  O  O21  1  0.358  0.227  0.423  1.0
  O  O22  1  0.992  0.358  0.423  1.0
  O  O23  1  0.227  0.992  0.423  1.0
  O  O24  1  0.575  0.227  0.766  1.0
  O  O25  1  0.432  0.575  0.766  1.0
  O  O26  1  0.227  0.432  0.766  1.0
  O  O27  1  0.727  0.075  0.266  1.0
  O  O28  1  0.932  0.727  0.266  1.0
  O  O29  1  0.075  0.932  0.266  1.0
  O  O30  1  0.428  0.777  0.234  1.0
  O  O31  1  0.561  0.428  0.234  1.0
  O  O32  1  0.777  0.561  0.234  1.0
  O  O33  1  0.277  0.928  0.734  1.0
  O  O34  1  0.061  0.277  0.734  1.0
  O  O35  1  0.928  0.061  0.734  1.0
  Si  Si36  1  0.247  0.963  0.244  1.0
  Si  Si37  1  0.545  0.247  0.244  1.0
  Si  Si38  1  0.963  0.545  0.244  1.0
  Si  Si39  1  0.463  0.747  0.744  1.0
  Si  Si40  1  0.045  0.463  0.744  1.0
  Si  Si41  1  0.747  0.045  0.744  1.0
[/CIF]
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The compound described by Na4NbGa(SiO4)3 crystallizes in the trigonal R3c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to three equivalent O(3) and three equivalent O(4) atoms. Nb(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form NbO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra. Ga(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form GaO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Ga(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. There are four inequivalent O sites. In the first O site, O(3) is bonded to one Na(2), two equivalent Na(1), one Ga(1), and one Si(1) atom to form distorted ONa3GaSi trigonal bipyramids that share corners with six equivalent O(4)Na3NbSi trigonal bipyramids,  an edgeedge with one O(4)Na3NbSi trigonal bipyramid, and faces with two equivalent O(3)Na3GaSi trigonal bipyramids. In the second O site, O(4) is bonded to one Na(2), two equivalent Na(1), one Nb(1), and one Si(1) atom to form distorted ONa3NbSi trigonal bipyramids that share corners with six equivalent O(3)Na3GaSi trigonal bipyramids,  an edgeedge with one O(3)Na3GaSi trigonal bipyramid, and faces with two equivalent O(4)Na3NbSi trigonal bipyramids. In the third O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1), one Ga(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(1), one Nb(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Na4NbGa(SiO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.061
_cell_length_b   9.061
_cell_length_c   9.063
_cell_angle_alpha   60.006
_cell_angle_beta   60.006
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   526.198
_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
  Ga  Ga0  1  0.351  0.351  0.947  1.0
  Ga  Ga1  1  0.851  0.851  0.447  1.0
  Na  Na2  1  0.238  0.621  0.256  1.0
  Na  Na3  1  0.885  0.238  0.256  1.0
  Na  Na4  1  0.621  0.885  0.256  1.0
  Na  Na5  1  0.121  0.738  0.756  1.0
  Na  Na6  1  0.385  0.121  0.756  1.0
  Na  Na7  1  0.738  0.385  0.756  1.0
  Na  Na8  1  0.495  0.495  0.514  1.0
  Na  Na9  1  0.995  0.995  0.014  1.0
  Nb  Nb10  1  0.647  0.647  0.060  1.0
  Nb  Nb11  1  0.147  0.147  0.560  1.0
  O  O12  1  0.274  0.141  0.069  1.0
  O  O13  1  0.516  0.274  0.069  1.0
  O  O14  1  0.141  0.516  0.069  1.0
  O  O15  1  0.641  0.774  0.569  1.0
  O  O16  1  0.016  0.641  0.569  1.0
  O  O17  1  0.774  0.016  0.569  1.0
  O  O18  1  0.727  0.858  0.923  1.0
  O  O19  1  0.492  0.727  0.923  1.0
  O  O20  1  0.858  0.492  0.923  1.0
  O  O21  1  0.358  0.227  0.423  1.0
  O  O22  1  0.992  0.358  0.423  1.0
  O  O23  1  0.227  0.992  0.423  1.0
  O  O24  1  0.575  0.227  0.766  1.0
  O  O25  1  0.432  0.575  0.766  1.0
  O  O26  1  0.227  0.432  0.766  1.0
  O  O27  1  0.727  0.075  0.266  1.0
  O  O28  1  0.932  0.727  0.266  1.0
  O  O29  1  0.075  0.932  0.266  1.0
  O  O30  1  0.428  0.777  0.234  1.0
  O  O31  1  0.561  0.428  0.234  1.0
  O  O32  1  0.777  0.561  0.234  1.0
  O  O33  1  0.277  0.928  0.734  1.0
  O  O34  1  0.061  0.277  0.734  1.0
  O  O35  1  0.928  0.061  0.734  1.0
  Si  Si36  1  0.247  0.963  0.244  1.0
  Si  Si37  1  0.545  0.247  0.244  1.0
  Si  Si38  1  0.963  0.545  0.244  1.0
  Si  Si39  1  0.463  0.747  0.744  1.0
  Si  Si40  1  0.045  0.463  0.744  1.0
  Si  Si41  1  0.747  0.045  0.744  1.0
[/CIF]
.