The material structure described by K4BaTa6(Si2O13)2 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to two equivalent O(5) and two equivalent O(6) atoms. In the second K site, K(2) is bonded in a 13-coordinate geometry to one O(2), two equivalent O(3), two equivalent O(4), two equivalent O(6), two equivalent O(8), and four equivalent O(7) atoms. Ba(1) is bonded in a 12-coordinate geometry to two equivalent O(1), two equivalent O(8), four equivalent O(3), and four equivalent O(4) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(3), one O(6), one O(7), one O(8), and one O(9) atom to form TaO6 octahedra that share  a cornercorner with one Ta(2)O6 octahedra, corners with three equivalent Ta(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 3-32°. In the second Ta site, Ta(2) is bonded to one O(10), one O(2), two equivalent O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 2-32°. Si(1) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ta(2)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-27°. There are ten inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(2), one Ba(1), one Ta(1), and one Si(1) atom. In the second O site, O(4) is bonded in a distorted bent 150 degrees geometry to one K(2), one Ba(1), one Ta(2), and one Si(1) atom. In the third O site, O(5) is bonded in a distorted linear geometry to two equivalent K(1) and two equivalent Si(1) atoms. In the fourth O site, O(6) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ta(1), and one Ta(2) atom. In the fifth O site, O(7) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(1), and one Si(1) atom. In the sixth O site, O(8) is bonded in a linear geometry to two equivalent K(2), one Ba(1), and two equivalent Ta(1) atoms. In the seventh O site, O(9) is bonded in a distorted linear geometry to two equivalent Ta(1) atoms. In the eighth O site, O(10) is bonded in a distorted linear geometry to two equivalent Ta(2) atoms. In the ninth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ba(1) and two equivalent Ta(1) atoms. In the tenth O site, O(2) is bonded in a linear geometry to two equivalent K(2) and two equivalent Ta(2) atoms. is represented by the CIF card [CIF]
data_K4BaTa6(Si2O13)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.167
_cell_length_b   9.167
_cell_length_c   7.872
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.626
_symmetry_Int_Tables_number   1
_cell_volume   575.061
_cell_formula_units_Z   1
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
  K  K0  1  0.611  0.001  0.000  1.0
  K  K1  1  0.595  0.999  0.500  1.0
  K  K2  1  0.999  0.595  0.500  1.0
  K  K3  1  0.001  0.611  0.000  1.0
  Ba  Ba4  1  0.397  0.397  0.500  1.0
  Ta  Ta5  1  0.999  0.238  0.751  1.0
  Ta  Ta6  1  0.999  0.238  0.249  1.0
  Ta  Ta7  1  0.238  0.999  0.249  1.0
  Ta  Ta8  1  0.238  0.999  0.751  1.0
  Ta  Ta9  1  0.764  0.764  0.250  1.0
  Ta  Ta10  1  0.764  0.764  0.750  1.0
  Si  Si11  1  0.335  0.664  0.792  1.0
  Si  Si12  1  0.335  0.664  0.208  1.0
  Si  Si13  1  0.664  0.335  0.792  1.0
  Si  Si14  1  0.664  0.335  0.208  1.0
  O  O15  1  0.174  0.174  0.240  1.0
  O  O16  1  0.769  0.769  0.500  1.0
  O  O17  1  0.184  0.485  0.724  1.0
  O  O18  1  0.184  0.485  0.276  1.0
  O  O19  1  0.514  0.694  0.722  1.0
  O  O20  1  0.514  0.694  0.278  1.0
  O  O21  1  0.335  0.666  0.000  1.0
  O  O22  1  0.824  0.001  0.762  1.0
  O  O23  1  0.824  0.001  0.238  1.0
  O  O24  1  0.305  0.817  0.270  1.0
  O  O25  1  0.305  0.817  0.730  1.0
  O  O26  1  0.004  0.236  0.500  1.0
  O  O27  1  0.996  0.268  0.000  1.0
  O  O28  1  0.001  0.824  0.238  1.0
  O  O29  1  0.268  0.996  0.000  1.0
  O  O30  1  0.236  0.004  0.500  1.0
  O  O31  1  0.817  0.305  0.270  1.0
  O  O32  1  0.817  0.305  0.730  1.0
  O  O33  1  0.485  0.184  0.724  1.0
  O  O34  1  0.485  0.184  0.276  1.0
  O  O35  1  0.666  0.335  0.000  1.0
  O  O36  1  0.174  0.174  0.760  1.0
  O  O37  1  0.694  0.514  0.722  1.0
  O  O38  1  0.694  0.514  0.278  1.0
  O  O39  1  0.001  0.824  0.762  1.0
  O  O40  1  0.737  0.737  0.000  1.0
[/CIF]
.
The material structure described by K4BaTa6(Si2O13)2 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to two equivalent O(5) and two equivalent O(6) atoms. In the second K site, K(2) is bonded in a 13-coordinate geometry to one O(2), two equivalent O(3), two equivalent O(4), two equivalent O(6), two equivalent O(8), and four equivalent O(7) atoms. Ba(1) is bonded in a 12-coordinate geometry to two equivalent O(1), two equivalent O(8), four equivalent O(3), and four equivalent O(4) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(3), one O(6), one O(7), one O(8), and one O(9) atom to form TaO6 octahedra that share  a cornercorner with one Ta(2)O6 octahedra, corners with three equivalent Ta(1)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 3-32°. In the second Ta site, Ta(2) is bonded to one O(10), one O(2), two equivalent O(4), and two equivalent O(6) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with two equivalent Ta(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 2-32°. Si(1) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ta(2)O6 octahedra, corners with two equivalent Ta(1)O6 octahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 23-27°. There are ten inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(2), one Ba(1), one Ta(1), and one Si(1) atom. In the second O site, O(4) is bonded in a distorted bent 150 degrees geometry to one K(2), one Ba(1), one Ta(2), and one Si(1) atom. In the third O site, O(5) is bonded in a distorted linear geometry to two equivalent K(1) and two equivalent Si(1) atoms. In the fourth O site, O(6) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ta(1), and one Ta(2) atom. In the fifth O site, O(7) is bonded in a distorted bent 150 degrees geometry to two equivalent K(2), one Ta(1), and one Si(1) atom. In the sixth O site, O(8) is bonded in a linear geometry to two equivalent K(2), one Ba(1), and two equivalent Ta(1) atoms. In the seventh O site, O(9) is bonded in a distorted linear geometry to two equivalent Ta(1) atoms. In the eighth O site, O(10) is bonded in a distorted linear geometry to two equivalent Ta(2) atoms. In the ninth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ba(1) and two equivalent Ta(1) atoms. In the tenth O site, O(2) is bonded in a linear geometry to two equivalent K(2) and two equivalent Ta(2) atoms. is represented by the CIF card [CIF]
data_K4BaTa6(Si2O13)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.167
_cell_length_b   9.167
_cell_length_c   7.872
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.626
_symmetry_Int_Tables_number   1
_cell_volume   575.061
_cell_formula_units_Z   1
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
  K  K0  1  0.611  0.001  0.000  1.0
  K  K1  1  0.595  0.999  0.500  1.0
  K  K2  1  0.999  0.595  0.500  1.0
  K  K3  1  0.001  0.611  0.000  1.0
  Ba  Ba4  1  0.397  0.397  0.500  1.0
  Ta  Ta5  1  0.999  0.238  0.751  1.0
  Ta  Ta6  1  0.999  0.238  0.249  1.0
  Ta  Ta7  1  0.238  0.999  0.249  1.0
  Ta  Ta8  1  0.238  0.999  0.751  1.0
  Ta  Ta9  1  0.764  0.764  0.250  1.0
  Ta  Ta10  1  0.764  0.764  0.750  1.0
  Si  Si11  1  0.335  0.664  0.792  1.0
  Si  Si12  1  0.335  0.664  0.208  1.0
  Si  Si13  1  0.664  0.335  0.792  1.0
  Si  Si14  1  0.664  0.335  0.208  1.0
  O  O15  1  0.174  0.174  0.240  1.0
  O  O16  1  0.769  0.769  0.500  1.0
  O  O17  1  0.184  0.485  0.724  1.0
  O  O18  1  0.184  0.485  0.276  1.0
  O  O19  1  0.514  0.694  0.722  1.0
  O  O20  1  0.514  0.694  0.278  1.0
  O  O21  1  0.335  0.666  0.000  1.0
  O  O22  1  0.824  0.001  0.762  1.0
  O  O23  1  0.824  0.001  0.238  1.0
  O  O24  1  0.305  0.817  0.270  1.0
  O  O25  1  0.305  0.817  0.730  1.0
  O  O26  1  0.004  0.236  0.500  1.0
  O  O27  1  0.996  0.268  0.000  1.0
  O  O28  1  0.001  0.824  0.238  1.0
  O  O29  1  0.268  0.996  0.000  1.0
  O  O30  1  0.236  0.004  0.500  1.0
  O  O31  1  0.817  0.305  0.270  1.0
  O  O32  1  0.817  0.305  0.730  1.0
  O  O33  1  0.485  0.184  0.724  1.0
  O  O34  1  0.485  0.184  0.276  1.0
  O  O35  1  0.666  0.335  0.000  1.0
  O  O36  1  0.174  0.174  0.760  1.0
  O  O37  1  0.694  0.514  0.722  1.0
  O  O38  1  0.694  0.514  0.278  1.0
  O  O39  1  0.001  0.824  0.762  1.0
  O  O40  1  0.737  0.737  0.000  1.0
[/CIF]
.