The structure described by Na2CoSiCO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(11), one O(12), one O(4), one O(5), one O(7), and one O(9) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Co(1)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Na(1)O7 pentagonal bipyramid,  an edgeedge with one Si(1)O4 tetrahedra,  a faceface with one Na(1)O7 pentagonal bipyramid, and  a faceface with one Co(1)O5 square pyramid. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(8) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(4), one O(7), one O(9), and two equivalent O(12) atoms to form distorted CoO5 square pyramids that share corners with two equivalent Na(1)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and faces with two equivalent Na(1)O7 pentagonal bipyramids. In the second Co site, Co(2) is bonded to one O(10), one O(8), and two equivalent O(11) atoms to form distorted CoO4 tetrahedra that share corners with two equivalent Na(1)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(8), one O(9), and two equivalent O(11) atoms to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O5 square pyramid, corners with three equivalent Co(2)O4 tetrahedra, and edges with two equivalent Na(1)O7 pentagonal bipyramids. In the second Si site, Si(2) is bonded to one O(10), one O(7), and two equivalent O(12) atoms to form SiO4 tetrahedra that share corners with four equivalent Na(1)O7 pentagonal bipyramids, corners with three equivalent Co(1)O5 square pyramids, and  a cornercorner with one Co(2)O4 tetrahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Co(1), and one C(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one C(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to two equivalent Na(1), one Co(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(2), one Co(2), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Co(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted tetrahedral geometry to two equivalent Na(2), one Co(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Co(2), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Na(1), one Co(1), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2CoSiCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.308
_cell_length_b   10.297
_cell_length_c   9.588
_cell_angle_alpha   90.769
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   622.728
_cell_formula_units_Z   4
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  0.006  0.128  0.239  1.0
  Na  Na1  1  0.998  0.615  0.241  1.0
  Na  Na2  1  0.494  0.128  0.239  1.0
  Na  Na3  1  0.502  0.615  0.241  1.0
  Na  Na4  1  0.498  0.385  0.759  1.0
  Na  Na5  1  0.506  0.872  0.761  1.0
  Na  Na6  1  0.002  0.385  0.759  1.0
  Na  Na7  1  0.994  0.872  0.761  1.0
  Co  Co8  1  0.750  0.909  0.366  1.0
  Co  Co9  1  0.250  0.091  0.634  1.0
  Co  Co10  1  0.750  0.395  0.399  1.0
  Co  Co11  1  0.250  0.605  0.601  1.0
  Si  Si12  1  0.250  0.337  0.435  1.0
  Si  Si13  1  0.250  0.848  0.425  1.0
  Si  Si14  1  0.750  0.152  0.576  1.0
  Si  Si15  1  0.750  0.663  0.565  1.0
  C  C16  1  0.750  0.365  0.058  1.0
  C  C17  1  0.750  0.865  0.077  1.0
  C  C18  1  0.250  0.135  0.923  1.0
  C  C19  1  0.250  0.635  0.942  1.0
  O  O20  1  0.250  0.120  0.054  1.0
  O  O21  1  0.250  0.632  0.075  1.0
  O  O22  1  0.750  0.368  0.925  1.0
  O  O23  1  0.750  0.880  0.946  1.0
  O  O24  1  0.750  0.470  0.130  1.0
  O  O25  1  0.750  0.969  0.158  1.0
  O  O26  1  0.250  0.031  0.842  1.0
  O  O27  1  0.250  0.530  0.870  1.0
  O  O28  1  0.750  0.256  0.120  1.0
  O  O29  1  0.750  0.755  0.136  1.0
  O  O30  1  0.250  0.245  0.864  1.0
  O  O31  1  0.250  0.745  0.880  1.0
  O  O32  1  0.750  0.095  0.416  1.0
  O  O33  1  0.750  0.580  0.418  1.0
  O  O34  1  0.250  0.420  0.582  1.0
  O  O35  1  0.250  0.905  0.584  1.0
  O  O36  1  0.250  0.177  0.459  1.0
  O  O37  1  0.250  0.686  0.424  1.0
  O  O38  1  0.750  0.314  0.576  1.0
  O  O39  1  0.750  0.823  0.541  1.0
  O  O40  1  0.034  0.367  0.343  1.0
  O  O41  1  0.040  0.893  0.335  1.0
  O  O42  1  0.466  0.367  0.343  1.0
  O  O43  1  0.460  0.893  0.335  1.0
  O  O44  1  0.540  0.107  0.665  1.0
  O  O45  1  0.534  0.633  0.657  1.0
  O  O46  1  0.960  0.107  0.665  1.0
  O  O47  1  0.966  0.633  0.657  1.0
[/CIF]
.
The structure described by Na2CoSiCO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(11), one O(12), one O(4), one O(5), one O(7), and one O(9) atom to form distorted NaO7 pentagonal bipyramids that share  a cornercorner with one Co(1)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Na(1)O7 pentagonal bipyramid,  an edgeedge with one Si(1)O4 tetrahedra,  a faceface with one Na(1)O7 pentagonal bipyramid, and  a faceface with one Co(1)O5 square pyramid. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(8) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(4), one O(7), one O(9), and two equivalent O(12) atoms to form distorted CoO5 square pyramids that share corners with two equivalent Na(1)O7 pentagonal bipyramids,  a cornercorner with one Si(1)O4 tetrahedra, corners with three equivalent Si(2)O4 tetrahedra, and faces with two equivalent Na(1)O7 pentagonal bipyramids. In the second Co site, Co(2) is bonded to one O(10), one O(8), and two equivalent O(11) atoms to form distorted CoO4 tetrahedra that share corners with two equivalent Na(1)O7 pentagonal bipyramids,  a cornercorner with one Si(2)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(8), one O(9), and two equivalent O(11) atoms to form SiO4 tetrahedra that share  a cornercorner with one Co(1)O5 square pyramid, corners with three equivalent Co(2)O4 tetrahedra, and edges with two equivalent Na(1)O7 pentagonal bipyramids. In the second Si site, Si(2) is bonded to one O(10), one O(7), and two equivalent O(12) atoms to form SiO4 tetrahedra that share corners with four equivalent Na(1)O7 pentagonal bipyramids, corners with three equivalent Co(1)O5 square pyramids, and  a cornercorner with one Co(2)O4 tetrahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Co(1), and one C(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(2) and one C(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to two equivalent Na(1), one Co(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(2), one Co(2), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Co(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted tetrahedral geometry to two equivalent Na(2), one Co(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Co(2), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a 2-coordinate geometry to one Na(1), one Co(1), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2CoSiCO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.308
_cell_length_b   10.297
_cell_length_c   9.588
_cell_angle_alpha   90.769
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   622.728
_cell_formula_units_Z   4
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  0.006  0.128  0.239  1.0
  Na  Na1  1  0.998  0.615  0.241  1.0
  Na  Na2  1  0.494  0.128  0.239  1.0
  Na  Na3  1  0.502  0.615  0.241  1.0
  Na  Na4  1  0.498  0.385  0.759  1.0
  Na  Na5  1  0.506  0.872  0.761  1.0
  Na  Na6  1  0.002  0.385  0.759  1.0
  Na  Na7  1  0.994  0.872  0.761  1.0
  Co  Co8  1  0.750  0.909  0.366  1.0
  Co  Co9  1  0.250  0.091  0.634  1.0
  Co  Co10  1  0.750  0.395  0.399  1.0
  Co  Co11  1  0.250  0.605  0.601  1.0
  Si  Si12  1  0.250  0.337  0.435  1.0
  Si  Si13  1  0.250  0.848  0.425  1.0
  Si  Si14  1  0.750  0.152  0.576  1.0
  Si  Si15  1  0.750  0.663  0.565  1.0
  C  C16  1  0.750  0.365  0.058  1.0
  C  C17  1  0.750  0.865  0.077  1.0
  C  C18  1  0.250  0.135  0.923  1.0
  C  C19  1  0.250  0.635  0.942  1.0
  O  O20  1  0.250  0.120  0.054  1.0
  O  O21  1  0.250  0.632  0.075  1.0
  O  O22  1  0.750  0.368  0.925  1.0
  O  O23  1  0.750  0.880  0.946  1.0
  O  O24  1  0.750  0.470  0.130  1.0
  O  O25  1  0.750  0.969  0.158  1.0
  O  O26  1  0.250  0.031  0.842  1.0
  O  O27  1  0.250  0.530  0.870  1.0
  O  O28  1  0.750  0.256  0.120  1.0
  O  O29  1  0.750  0.755  0.136  1.0
  O  O30  1  0.250  0.245  0.864  1.0
  O  O31  1  0.250  0.745  0.880  1.0
  O  O32  1  0.750  0.095  0.416  1.0
  O  O33  1  0.750  0.580  0.418  1.0
  O  O34  1  0.250  0.420  0.582  1.0
  O  O35  1  0.250  0.905  0.584  1.0
  O  O36  1  0.250  0.177  0.459  1.0
  O  O37  1  0.250  0.686  0.424  1.0
  O  O38  1  0.750  0.314  0.576  1.0
  O  O39  1  0.750  0.823  0.541  1.0
  O  O40  1  0.034  0.367  0.343  1.0
  O  O41  1  0.040  0.893  0.335  1.0
  O  O42  1  0.466  0.367  0.343  1.0
  O  O43  1  0.460  0.893  0.335  1.0
  O  O44  1  0.540  0.107  0.665  1.0
  O  O45  1  0.534  0.633  0.657  1.0
  O  O46  1  0.960  0.107  0.665  1.0
  O  O47  1  0.966  0.633  0.657  1.0
[/CIF]
.