The crystal structure described by Na2Cu5(Si2O7)2 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(7), and two equivalent O(5) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(6), and one O(7) atom. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to two equivalent O(6) and two equivalent O(7) atoms. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(3), one O(5), and two equivalent O(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Cu(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded to one Na(1), one Cu(1), one Cu(3), and one Si(2) atom to form distorted ONaCu2Si tetrahedra that share  a cornercorner with one O(5)Na2CuSi trigonal pyramid, corners with two equivalent O(7)NaCu2Si trigonal pyramids, and  an edgeedge with one O(5)Na2CuSi trigonal pyramid. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cu(3) and one Si(2) atom. In the fifth O site, O(5) is bonded to two equivalent Na(1), one Cu(3), and one Si(1) atom to form distorted ONa2CuSi trigonal pyramids that share  a cornercorner with one O(3)NaCu2Si tetrahedra,  a cornercorner with one O(7)NaCu2Si trigonal pyramid,  an edgeedge with one O(3)NaCu2Si tetrahedra,  an edgeedge with one O(5)Na2CuSi trigonal pyramid, and  an edgeedge with one O(7)NaCu2Si trigonal pyramid. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Na(1), one Cu(1), one Cu(2), and one Si(1) atom to form distorted ONaCu2Si trigonal pyramids that share corners with two equivalent O(3)NaCu2Si tetrahedra,  a cornercorner with one O(5)Na2CuSi trigonal pyramid,  a cornercorner with one O(7)NaCu2Si trigonal pyramid, and  an edgeedge with one O(5)Na2CuSi trigonal pyramid. is represented by the CIF card [CIF]
data_Na2Cu5(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.834
_cell_length_b   7.927
_cell_length_c   8.114
_cell_angle_alpha   63.319
_cell_angle_beta   86.926
_cell_angle_gamma   68.917
_symmetry_Int_Tables_number   1
_cell_volume   310.206
_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
  Na  Na0  1  0.232  0.631  0.059  1.0
  Na  Na1  1  0.768  0.369  0.941  1.0
  Cu  Cu2  1  0.815  0.065  0.774  1.0
  Cu  Cu3  1  0.500  0.500  0.500  1.0
  Cu  Cu4  1  0.185  0.935  0.226  1.0
  Cu  Cu5  1  0.417  0.896  0.681  1.0
  Cu  Cu6  1  0.583  0.104  0.319  1.0
  Si  Si7  1  0.691  0.713  0.091  1.0
  Si  Si8  1  0.986  0.261  0.365  1.0
  Si  Si9  1  0.014  0.739  0.635  1.0
  Si  Si10  1  0.309  0.287  0.909  1.0
  O  O11  1  0.196  0.110  0.971  1.0
  O  O12  1  0.064  0.504  0.794  1.0
  O  O13  1  0.091  0.858  0.733  1.0
  O  O14  1  0.909  0.142  0.267  1.0
  O  O15  1  0.280  0.144  0.449  1.0
  O  O16  1  0.423  0.304  0.077  1.0
  O  O17  1  0.936  0.496  0.206  1.0
  O  O18  1  0.804  0.890  0.029  1.0
  O  O19  1  0.720  0.856  0.551  1.0
  O  O20  1  0.807  0.279  0.525  1.0
  O  O21  1  0.486  0.705  0.243  1.0
  O  O22  1  0.514  0.295  0.757  1.0
  O  O23  1  0.193  0.721  0.475  1.0
  O  O24  1  0.577  0.696  0.923  1.0
[/CIF]
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The crystal structure described by Na2Cu5(Si2O7)2 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(7), and two equivalent O(5) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(6), and one O(7) atom. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to two equivalent O(6) and two equivalent O(7) atoms. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one O(3), one O(5), and two equivalent O(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Cu(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded to one Na(1), one Cu(1), one Cu(3), and one Si(2) atom to form distorted ONaCu2Si tetrahedra that share  a cornercorner with one O(5)Na2CuSi trigonal pyramid, corners with two equivalent O(7)NaCu2Si trigonal pyramids, and  an edgeedge with one O(5)Na2CuSi trigonal pyramid. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cu(3) and one Si(2) atom. In the fifth O site, O(5) is bonded to two equivalent Na(1), one Cu(3), and one Si(1) atom to form distorted ONa2CuSi trigonal pyramids that share  a cornercorner with one O(3)NaCu2Si tetrahedra,  a cornercorner with one O(7)NaCu2Si trigonal pyramid,  an edgeedge with one O(3)NaCu2Si tetrahedra,  an edgeedge with one O(5)Na2CuSi trigonal pyramid, and  an edgeedge with one O(7)NaCu2Si trigonal pyramid. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one Si(2) atom. In the seventh O site, O(7) is bonded to one Na(1), one Cu(1), one Cu(2), and one Si(1) atom to form distorted ONaCu2Si trigonal pyramids that share corners with two equivalent O(3)NaCu2Si tetrahedra,  a cornercorner with one O(5)Na2CuSi trigonal pyramid,  a cornercorner with one O(7)NaCu2Si trigonal pyramid, and  an edgeedge with one O(5)Na2CuSi trigonal pyramid. is represented by the CIF card [CIF]
data_Na2Cu5(Si2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.834
_cell_length_b   7.927
_cell_length_c   8.114
_cell_angle_alpha   63.319
_cell_angle_beta   86.926
_cell_angle_gamma   68.917
_symmetry_Int_Tables_number   1
_cell_volume   310.206
_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
  Na  Na0  1  0.232  0.631  0.059  1.0
  Na  Na1  1  0.768  0.369  0.941  1.0
  Cu  Cu2  1  0.815  0.065  0.774  1.0
  Cu  Cu3  1  0.500  0.500  0.500  1.0
  Cu  Cu4  1  0.185  0.935  0.226  1.0
  Cu  Cu5  1  0.417  0.896  0.681  1.0
  Cu  Cu6  1  0.583  0.104  0.319  1.0
  Si  Si7  1  0.691  0.713  0.091  1.0
  Si  Si8  1  0.986  0.261  0.365  1.0
  Si  Si9  1  0.014  0.739  0.635  1.0
  Si  Si10  1  0.309  0.287  0.909  1.0
  O  O11  1  0.196  0.110  0.971  1.0
  O  O12  1  0.064  0.504  0.794  1.0
  O  O13  1  0.091  0.858  0.733  1.0
  O  O14  1  0.909  0.142  0.267  1.0
  O  O15  1  0.280  0.144  0.449  1.0
  O  O16  1  0.423  0.304  0.077  1.0
  O  O17  1  0.936  0.496  0.206  1.0
  O  O18  1  0.804  0.890  0.029  1.0
  O  O19  1  0.720  0.856  0.551  1.0
  O  O20  1  0.807  0.279  0.525  1.0
  O  O21  1  0.486  0.705  0.243  1.0
  O  O22  1  0.514  0.295  0.757  1.0
  O  O23  1  0.193  0.721  0.475  1.0
  O  O24  1  0.577  0.696  0.923  1.0
[/CIF]
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