The crystal structure described by Na4LaTa(SiO4)3 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the trigonal R3c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 3-coordinate geometry to one O(1), one O(4), and two equivalent O(3) 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. La(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form distorted LaO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra. 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 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 La(1)O6 octahedra and corners with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-48°. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one La(1), and one Si(1) atom. In the second O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Ta(1), and one Si(1) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one La(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted linear geometry to one Ta(1) and one Si(1) atom. is represented by the CIF card [CIF]
data_Na4LaTa(SiO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.237
_cell_length_b   9.237
_cell_length_c   9.237
_cell_angle_alpha   62.108
_cell_angle_beta   62.108
_cell_angle_gamma   62.108
_symmetry_Int_Tables_number   1
_cell_volume   583.537
_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
  La  La0  1  0.342  0.342  0.342  1.0
  La  La1  1  0.842  0.842  0.842  1.0
  Na  Na2  1  0.890  0.613  0.232  1.0
  Na  Na3  1  0.613  0.232  0.890  1.0
  Na  Na4  1  0.232  0.890  0.613  1.0
  Na  Na5  1  0.390  0.732  0.113  1.0
  Na  Na6  1  0.732  0.113  0.390  1.0
  Na  Na7  1  0.113  0.390  0.732  1.0
  Na  Na8  1  0.496  0.496  0.496  1.0
  Na  Na9  1  0.996  0.996  0.996  1.0
  O  O10  1  0.549  0.092  0.301  1.0
  O  O11  1  0.092  0.301  0.549  1.0
  O  O12  1  0.301  0.549  0.092  1.0
  O  O13  1  0.049  0.801  0.592  1.0
  O  O14  1  0.801  0.592  0.049  1.0
  O  O15  1  0.592  0.049  0.801  1.0
  O  O16  1  0.504  0.857  0.728  1.0
  O  O17  1  0.857  0.728  0.504  1.0
  O  O18  1  0.728  0.504  0.857  1.0
  O  O19  1  0.004  0.228  0.357  1.0
  O  O20  1  0.228  0.357  0.004  1.0
  O  O21  1  0.357  0.004  0.228  1.0
  O  O22  1  0.393  0.223  0.614  1.0
  O  O23  1  0.223  0.614  0.393  1.0
  O  O24  1  0.614  0.393  0.223  1.0
  O  O25  1  0.893  0.114  0.723  1.0
  O  O26  1  0.114  0.723  0.893  1.0
  O  O27  1  0.723  0.893  0.114  1.0
  O  O28  1  0.540  0.770  0.452  1.0
  O  O29  1  0.770  0.452  0.540  1.0
  O  O30  1  0.452  0.540  0.770  1.0
  O  O31  1  0.040  0.952  0.270  1.0
  O  O32  1  0.952  0.270  0.040  1.0
  O  O33  1  0.270  0.040  0.952  1.0
  Si  Si34  1  0.547  0.938  0.268  1.0
  Si  Si35  1  0.938  0.268  0.547  1.0
  Si  Si36  1  0.268  0.547  0.938  1.0
  Si  Si37  1  0.047  0.768  0.438  1.0
  Si  Si38  1  0.768  0.438  0.047  1.0
  Si  Si39  1  0.438  0.047  0.768  1.0
  Ta  Ta40  1  0.648  0.648  0.648  1.0
  Ta  Ta41  1  0.148  0.148  0.148  1.0
[/CIF]
.
The crystal structure described by Na4LaTa(SiO4)3 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the trigonal R3c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 3-coordinate geometry to one O(1), one O(4), and two equivalent O(3) 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. La(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form distorted LaO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra. 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 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 La(1)O6 octahedra and corners with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-48°. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(1), one La(1), and one Si(1) atom. In the second O site, O(4) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Ta(1), and one Si(1) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one La(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a distorted linear geometry to one Ta(1) and one Si(1) atom. is represented by the CIF card [CIF]
data_Na4LaTa(SiO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.237
_cell_length_b   9.237
_cell_length_c   9.237
_cell_angle_alpha   62.108
_cell_angle_beta   62.108
_cell_angle_gamma   62.108
_symmetry_Int_Tables_number   1
_cell_volume   583.537
_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
  La  La0  1  0.342  0.342  0.342  1.0
  La  La1  1  0.842  0.842  0.842  1.0
  Na  Na2  1  0.890  0.613  0.232  1.0
  Na  Na3  1  0.613  0.232  0.890  1.0
  Na  Na4  1  0.232  0.890  0.613  1.0
  Na  Na5  1  0.390  0.732  0.113  1.0
  Na  Na6  1  0.732  0.113  0.390  1.0
  Na  Na7  1  0.113  0.390  0.732  1.0
  Na  Na8  1  0.496  0.496  0.496  1.0
  Na  Na9  1  0.996  0.996  0.996  1.0
  O  O10  1  0.549  0.092  0.301  1.0
  O  O11  1  0.092  0.301  0.549  1.0
  O  O12  1  0.301  0.549  0.092  1.0
  O  O13  1  0.049  0.801  0.592  1.0
  O  O14  1  0.801  0.592  0.049  1.0
  O  O15  1  0.592  0.049  0.801  1.0
  O  O16  1  0.504  0.857  0.728  1.0
  O  O17  1  0.857  0.728  0.504  1.0
  O  O18  1  0.728  0.504  0.857  1.0
  O  O19  1  0.004  0.228  0.357  1.0
  O  O20  1  0.228  0.357  0.004  1.0
  O  O21  1  0.357  0.004  0.228  1.0
  O  O22  1  0.393  0.223  0.614  1.0
  O  O23  1  0.223  0.614  0.393  1.0
  O  O24  1  0.614  0.393  0.223  1.0
  O  O25  1  0.893  0.114  0.723  1.0
  O  O26  1  0.114  0.723  0.893  1.0
  O  O27  1  0.723  0.893  0.114  1.0
  O  O28  1  0.540  0.770  0.452  1.0
  O  O29  1  0.770  0.452  0.540  1.0
  O  O30  1  0.452  0.540  0.770  1.0
  O  O31  1  0.040  0.952  0.270  1.0
  O  O32  1  0.952  0.270  0.040  1.0
  O  O33  1  0.270  0.040  0.952  1.0
  Si  Si34  1  0.547  0.938  0.268  1.0
  Si  Si35  1  0.938  0.268  0.547  1.0
  Si  Si36  1  0.268  0.547  0.938  1.0
  Si  Si37  1  0.047  0.768  0.438  1.0
  Si  Si38  1  0.768  0.438  0.047  1.0
  Si  Si39  1  0.438  0.047  0.768  1.0
  Ta  Ta40  1  0.648  0.648  0.648  1.0
  Ta  Ta41  1  0.148  0.148  0.148  1.0
[/CIF]
.