The material structure described by Na2Co(Si2O5)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(8), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(10), one O(6), one O(7), and two equivalent O(5) atoms. Co(1) is bonded to one O(10), one O(5), one O(7), and two equivalent O(6) atoms to form CoO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Co(1)O5 trigonal bipyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Co(1)O5 trigonal bipyramids. In the fourth Si site, Si(4) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Co(1), and one Si(2) atom. In the second O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(2), and one Si(4) atom. In the third O site, O(2) is bonded in a 2-coordinate geometry to one Na(1), one Si(1), and one Si(3) atom. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Si(3), and one Si(4) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Si(1), and one Si(4) atom. In the sixth O site, O(5) is bonded to two equivalent Na(2), one Co(1), and one Si(4) atom to form distorted edge-sharing ONa2CoSi trigonal pyramids. In the seventh O site, O(6) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Co(1), and one Si(3) atom. In the eighth O site, O(7) is bonded in a trigonal non-coplanar geometry to one Na(2), one Co(1), and one Si(1) atom. In the ninth O site, O(8) is bonded in a distorted trigonal planar geometry to one Na(1), one Si(1), and one Si(2) atom. In the tenth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Si(2) and one Si(3) atom. is represented by the CIF card [CIF]
data_Na2Co(Si2O5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.016
_cell_length_b   7.875
_cell_length_c   9.883
_cell_angle_alpha   102.179
_cell_angle_beta   102.251
_cell_angle_gamma   114.837
_symmetry_Int_Tables_number   1
_cell_volume   455.674
_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
  Na  Na0  1  0.656  0.768  0.984  1.0
  Na  Na1  1  0.738  0.275  0.421  1.0
  Na  Na2  1  0.262  0.725  0.579  1.0
  Na  Na3  1  0.344  0.232  0.016  1.0
  Co  Co4  1  0.755  0.692  0.581  1.0
  Co  Co5  1  0.245  0.308  0.419  1.0
  Si  Si6  1  0.090  0.713  0.862  1.0
  Si  Si7  1  0.910  0.287  0.138  1.0
  Si  Si8  1  0.235  0.928  0.198  1.0
  Si  Si9  1  0.765  0.072  0.802  1.0
  Si  Si10  1  0.388  0.628  0.259  1.0
  Si  Si11  1  0.190  0.381  0.752  1.0
  Si  Si12  1  0.810  0.619  0.248  1.0
  Si  Si13  1  0.612  0.372  0.741  1.0
  O  O14  1  0.981  0.792  0.198  1.0
  O  O15  1  0.019  0.208  0.802  1.0
  O  O16  1  0.848  0.553  0.867  1.0
  O  O17  1  0.152  0.447  0.133  1.0
  O  O18  1  0.574  0.622  0.182  1.0
  O  O19  1  0.426  0.378  0.818  1.0
  O  O20  1  0.247  0.602  0.860  1.0
  O  O21  1  0.753  0.398  0.140  1.0
  O  O22  1  0.886  0.645  0.418  1.0
  O  O23  1  0.114  0.355  0.582  1.0
  O  O24  1  0.427  0.598  0.416  1.0
  O  O25  1  0.573  0.402  0.584  1.0
  O  O26  1  0.064  0.791  0.727  1.0
  O  O27  1  0.936  0.209  0.273  1.0
  O  O28  1  0.785  0.104  0.978  1.0
  O  O29  1  0.215  0.896  0.022  1.0
  O  O30  1  0.605  0.158  0.730  1.0
  O  O31  1  0.395  0.842  0.270  1.0
  O  O32  1  0.345  0.161  0.281  1.0
  O  O33  1  0.655  0.839  0.719  1.0
[/CIF]
.
The material structure described by Na2Co(Si2O5)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(8), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(10), one O(6), one O(7), and two equivalent O(5) atoms. Co(1) is bonded to one O(10), one O(5), one O(7), and two equivalent O(6) atoms to form CoO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and  an edgeedge with one Co(1)O5 trigonal bipyramid. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(4), one O(7), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the third Si site, Si(3) is bonded to one O(2), one O(3), one O(6), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and corners with two equivalent Co(1)O5 trigonal bipyramids. In the fourth Si site, Si(4) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Co(1), and one Si(2) atom. In the second O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(2), and one Si(4) atom. In the third O site, O(2) is bonded in a 2-coordinate geometry to one Na(1), one Si(1), and one Si(3) atom. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Si(3), and one Si(4) atom. In the fifth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Si(1), and one Si(4) atom. In the sixth O site, O(5) is bonded to two equivalent Na(2), one Co(1), and one Si(4) atom to form distorted edge-sharing ONa2CoSi trigonal pyramids. In the seventh O site, O(6) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Co(1), and one Si(3) atom. In the eighth O site, O(7) is bonded in a trigonal non-coplanar geometry to one Na(2), one Co(1), and one Si(1) atom. In the ninth O site, O(8) is bonded in a distorted trigonal planar geometry to one Na(1), one Si(1), and one Si(2) atom. In the tenth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Si(2) and one Si(3) atom. is represented by the CIF card [CIF]
data_Na2Co(Si2O5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.016
_cell_length_b   7.875
_cell_length_c   9.883
_cell_angle_alpha   102.179
_cell_angle_beta   102.251
_cell_angle_gamma   114.837
_symmetry_Int_Tables_number   1
_cell_volume   455.674
_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
  Na  Na0  1  0.656  0.768  0.984  1.0
  Na  Na1  1  0.738  0.275  0.421  1.0
  Na  Na2  1  0.262  0.725  0.579  1.0
  Na  Na3  1  0.344  0.232  0.016  1.0
  Co  Co4  1  0.755  0.692  0.581  1.0
  Co  Co5  1  0.245  0.308  0.419  1.0
  Si  Si6  1  0.090  0.713  0.862  1.0
  Si  Si7  1  0.910  0.287  0.138  1.0
  Si  Si8  1  0.235  0.928  0.198  1.0
  Si  Si9  1  0.765  0.072  0.802  1.0
  Si  Si10  1  0.388  0.628  0.259  1.0
  Si  Si11  1  0.190  0.381  0.752  1.0
  Si  Si12  1  0.810  0.619  0.248  1.0
  Si  Si13  1  0.612  0.372  0.741  1.0
  O  O14  1  0.981  0.792  0.198  1.0
  O  O15  1  0.019  0.208  0.802  1.0
  O  O16  1  0.848  0.553  0.867  1.0
  O  O17  1  0.152  0.447  0.133  1.0
  O  O18  1  0.574  0.622  0.182  1.0
  O  O19  1  0.426  0.378  0.818  1.0
  O  O20  1  0.247  0.602  0.860  1.0
  O  O21  1  0.753  0.398  0.140  1.0
  O  O22  1  0.886  0.645  0.418  1.0
  O  O23  1  0.114  0.355  0.582  1.0
  O  O24  1  0.427  0.598  0.416  1.0
  O  O25  1  0.573  0.402  0.584  1.0
  O  O26  1  0.064  0.791  0.727  1.0
  O  O27  1  0.936  0.209  0.273  1.0
  O  O28  1  0.785  0.104  0.978  1.0
  O  O29  1  0.215  0.896  0.022  1.0
  O  O30  1  0.605  0.158  0.730  1.0
  O  O31  1  0.395  0.842  0.270  1.0
  O  O32  1  0.345  0.161  0.281  1.0
  O  O33  1  0.655  0.839  0.719  1.0
[/CIF]
.