The structure described by Na3NbGeSi3O12 crystallizes in the monoclinic Cc space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar 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 8-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(2), one O(7), one O(8), 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(2), one O(5), one O(6), one O(7), and two equivalent O(4) atoms. 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 Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. Ge(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 GeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(12), 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 Ge(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-41°. In the second Si site, Si(2) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Ge(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-36°. In the third Si site, Si(3) 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 Nb(1)O6 octahedra and corners with two equivalent Ge(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-37°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ge(1), and one Si(3) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Nb(1), and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(3), one Ge(1), and one Si(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 Ge(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Nb(1), and one Si(3) 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 Si(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Ge(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Ge(1), and one Si(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Nb(1), and one Si(3) 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 Ge(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Nb(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Na3NbSi3GeO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.881
_cell_length_b   8.947
_cell_length_c   8.920
_cell_angle_alpha   119.874
_cell_angle_beta   90.000
_cell_angle_gamma   119.757
_symmetry_Int_Tables_number   1
_cell_volume   503.945
_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
  Ge  Ge0  1  0.147  0.790  0.433  1.0
  Ge  Ge1  1  0.643  0.790  0.933  1.0
  Na  Na2  1  0.023  0.502  0.008  1.0
  Na  Na3  1  0.479  0.502  0.508  1.0
  Na  Na4  1  0.392  0.008  0.256  1.0
  Na  Na5  1  0.616  0.008  0.756  1.0
  Na  Na6  1  0.866  0.617  0.719  1.0
  Na  Na7  1  0.750  0.617  0.219  1.0
  Nb  Nb8  1  0.353  0.216  0.071  1.0
  Nb  Nb9  1  0.862  0.216  0.571  1.0
  O  O10  1  0.275  0.713  0.264  1.0
  O  O11  1  0.588  0.307  0.235  1.0
  O  O12  1  0.720  0.307  0.735  1.0
  O  O13  1  0.439  0.713  0.764  1.0
  O  O14  1  0.993  0.125  0.421  1.0
  O  O15  1  0.856  0.841  0.059  1.0
  O  O16  1  0.985  0.841  0.559  1.0
  O  O17  1  0.133  0.125  0.921  1.0
  O  O18  1  0.937  0.499  0.260  1.0
  O  O19  1  0.446  0.523  0.240  1.0
  O  O20  1  0.077  0.523  0.740  1.0
  O  O21  1  0.562  0.499  0.760  1.0
  O  O22  1  0.792  0.293  0.424  1.0
  O  O23  1  0.504  0.732  0.078  1.0
  O  O24  1  0.227  0.732  0.578  1.0
  O  O25  1  0.501  0.293  0.924  1.0
  O  O26  1  0.722  0.076  0.058  1.0
  O  O27  1  0.633  0.930  0.439  1.0
  O  O28  1  0.297  0.930  0.939  1.0
  O  O29  1  0.354  0.076  0.558  1.0
  O  O30  1  0.059  0.827  0.256  1.0
  O  O31  1  0.231  0.162  0.246  1.0
  O  O32  1  0.931  0.162  0.746  1.0
  O  O33  1  0.767  0.827  0.756  1.0
  Si  Si34  1  0.034  0.989  0.241  1.0
  Si  Si35  1  0.955  0.989  0.741  1.0
  Si  Si36  1  0.768  0.292  0.241  1.0
  Si  Si37  1  0.460  0.719  0.251  1.0
  Si  Si38  1  0.259  0.719  0.751  1.0
  Si  Si39  1  0.525  0.292  0.741  1.0
[/CIF]
.
The structure described by Na3NbGeSi3O12 crystallizes in the monoclinic Cc space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar 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 8-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(2), one O(7), one O(8), 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(2), one O(5), one O(6), one O(7), and two equivalent O(4) atoms. 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 Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. Ge(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 GeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(12), 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 Ge(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-41°. In the second Si site, Si(2) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Ge(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-36°. In the third Si site, Si(3) 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 Nb(1)O6 octahedra and corners with two equivalent Ge(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-37°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ge(1), and one Si(3) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Nb(1), and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(3), one Ge(1), and one Si(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 Ge(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Nb(1), and one Si(3) 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 Si(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Ge(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Ge(1), and one Si(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Nb(1), and one Si(3) 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 Ge(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Nb(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Na3NbSi3GeO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.881
_cell_length_b   8.947
_cell_length_c   8.920
_cell_angle_alpha   119.874
_cell_angle_beta   90.000
_cell_angle_gamma   119.757
_symmetry_Int_Tables_number   1
_cell_volume   503.945
_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
  Ge  Ge0  1  0.147  0.790  0.433  1.0
  Ge  Ge1  1  0.643  0.790  0.933  1.0
  Na  Na2  1  0.023  0.502  0.008  1.0
  Na  Na3  1  0.479  0.502  0.508  1.0
  Na  Na4  1  0.392  0.008  0.256  1.0
  Na  Na5  1  0.616  0.008  0.756  1.0
  Na  Na6  1  0.866  0.617  0.719  1.0
  Na  Na7  1  0.750  0.617  0.219  1.0
  Nb  Nb8  1  0.353  0.216  0.071  1.0
  Nb  Nb9  1  0.862  0.216  0.571  1.0
  O  O10  1  0.275  0.713  0.264  1.0
  O  O11  1  0.588  0.307  0.235  1.0
  O  O12  1  0.720  0.307  0.735  1.0
  O  O13  1  0.439  0.713  0.764  1.0
  O  O14  1  0.993  0.125  0.421  1.0
  O  O15  1  0.856  0.841  0.059  1.0
  O  O16  1  0.985  0.841  0.559  1.0
  O  O17  1  0.133  0.125  0.921  1.0
  O  O18  1  0.937  0.499  0.260  1.0
  O  O19  1  0.446  0.523  0.240  1.0
  O  O20  1  0.077  0.523  0.740  1.0
  O  O21  1  0.562  0.499  0.760  1.0
  O  O22  1  0.792  0.293  0.424  1.0
  O  O23  1  0.504  0.732  0.078  1.0
  O  O24  1  0.227  0.732  0.578  1.0
  O  O25  1  0.501  0.293  0.924  1.0
  O  O26  1  0.722  0.076  0.058  1.0
  O  O27  1  0.633  0.930  0.439  1.0
  O  O28  1  0.297  0.930  0.939  1.0
  O  O29  1  0.354  0.076  0.558  1.0
  O  O30  1  0.059  0.827  0.256  1.0
  O  O31  1  0.231  0.162  0.246  1.0
  O  O32  1  0.931  0.162  0.746  1.0
  O  O33  1  0.767  0.827  0.756  1.0
  Si  Si34  1  0.034  0.989  0.241  1.0
  Si  Si35  1  0.955  0.989  0.741  1.0
  Si  Si36  1  0.768  0.292  0.241  1.0
  Si  Si37  1  0.460  0.719  0.251  1.0
  Si  Si38  1  0.259  0.719  0.751  1.0
  Si  Si39  1  0.525  0.292  0.741  1.0
[/CIF]
.