The structure described by Na2V2O5 is Chalcostibite-like structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), one O(5), and two equivalent O(1) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent V(1)O4 tetrahedra, corners with three equivalent V(2)O4 tetrahedra, corners with two equivalent Na(2)O4 trigonal pyramids,  an edgeedge with one V(2)O4 tetrahedra,  an edgeedge with one Na(1)O5 trigonal bipyramid, and  an edgeedge with one Na(2)O4 trigonal pyramid. In the second Na site, Na(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form NaO4 trigonal pyramids that share  a cornercorner with one V(2)O4 tetrahedra, corners with four equivalent V(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids,  an edgeedge with one Na(1)O5 trigonal bipyramid, and  an edgeedge with one Na(2)O4 trigonal pyramid. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(5), and two equivalent O(4) atoms to form VO4 tetrahedra that share  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, and corners with four equivalent Na(2)O4 trigonal pyramids. In the second V site, V(2) is bonded to one O(1), one O(5), and two equivalent O(3) atoms to form VO4 tetrahedra that share  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, corners with three equivalent Na(1)O5 trigonal bipyramids,  a cornercorner with one Na(2)O4 trigonal pyramid, and  an edgeedge with one Na(1)O5 trigonal bipyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(1), and one V(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one V(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Na(1) and two equivalent V(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2) and two equivalent V(1) atoms. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Na(1), one V(1), and one V(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2V2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.440
_cell_length_b   8.711
_cell_length_c   12.444
_cell_angle_alpha   77.589
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   575.992
_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  0.697  0.147  0.031  1.0
  Na  Na1  1  0.268  0.385  0.057  1.0
  Na  Na2  1  0.768  0.615  0.443  1.0
  Na  Na3  1  0.803  0.147  0.531  1.0
  Na  Na4  1  0.197  0.853  0.469  1.0
  Na  Na5  1  0.232  0.385  0.557  1.0
  Na  Na6  1  0.732  0.615  0.943  1.0
  Na  Na7  1  0.303  0.853  0.969  1.0
  V  V8  1  0.801  0.398  0.226  1.0
  V  V9  1  0.667  0.022  0.326  1.0
  V  V10  1  0.167  0.978  0.174  1.0
  V  V11  1  0.301  0.602  0.274  1.0
  V  V12  1  0.699  0.398  0.726  1.0
  V  V13  1  0.833  0.022  0.826  1.0
  V  V14  1  0.333  0.978  0.674  1.0
  V  V15  1  0.199  0.602  0.774  1.0
  O  O16  1  0.268  0.113  0.061  1.0
  O  O17  1  0.712  0.396  0.091  1.0
  O  O18  1  0.341  0.004  0.298  1.0
  O  O19  1  0.133  0.441  0.226  1.0
  O  O20  1  0.242  0.774  0.161  1.0
  O  O21  1  0.742  0.226  0.339  1.0
  O  O22  1  0.633  0.559  0.274  1.0
  O  O23  1  0.841  0.996  0.202  1.0
  O  O24  1  0.212  0.604  0.409  1.0
  O  O25  1  0.232  0.113  0.561  1.0
  O  O26  1  0.768  0.887  0.439  1.0
  O  O27  1  0.788  0.396  0.591  1.0
  O  O28  1  0.159  0.004  0.798  1.0
  O  O29  1  0.367  0.441  0.726  1.0
  O  O30  1  0.258  0.774  0.661  1.0
  O  O31  1  0.758  0.226  0.839  1.0
  O  O32  1  0.867  0.559  0.774  1.0
  O  O33  1  0.659  0.996  0.702  1.0
  O  O34  1  0.288  0.604  0.909  1.0
  O  O35  1  0.732  0.887  0.939  1.0
[/CIF]
.
The structure described by Na2V2O5 is Chalcostibite-like structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2), one O(3), one O(5), and two equivalent O(1) atoms to form distorted NaO5 trigonal bipyramids that share corners with two equivalent V(1)O4 tetrahedra, corners with three equivalent V(2)O4 tetrahedra, corners with two equivalent Na(2)O4 trigonal pyramids,  an edgeedge with one V(2)O4 tetrahedra,  an edgeedge with one Na(1)O5 trigonal bipyramid, and  an edgeedge with one Na(2)O4 trigonal pyramid. In the second Na site, Na(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form NaO4 trigonal pyramids that share  a cornercorner with one V(2)O4 tetrahedra, corners with four equivalent V(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids,  an edgeedge with one Na(1)O5 trigonal bipyramid, and  an edgeedge with one Na(2)O4 trigonal pyramid. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(5), and two equivalent O(4) atoms to form VO4 tetrahedra that share  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, and corners with four equivalent Na(2)O4 trigonal pyramids. In the second V site, V(2) is bonded to one O(1), one O(5), and two equivalent O(3) atoms to form VO4 tetrahedra that share  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, corners with three equivalent Na(1)O5 trigonal bipyramids,  a cornercorner with one Na(2)O4 trigonal pyramid, and  an edgeedge with one Na(1)O5 trigonal bipyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(1), and one V(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one V(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Na(1) and two equivalent V(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(2) and two equivalent V(1) atoms. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Na(1), one V(1), and one V(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2V2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.440
_cell_length_b   8.711
_cell_length_c   12.444
_cell_angle_alpha   77.589
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   575.992
_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  0.697  0.147  0.031  1.0
  Na  Na1  1  0.268  0.385  0.057  1.0
  Na  Na2  1  0.768  0.615  0.443  1.0
  Na  Na3  1  0.803  0.147  0.531  1.0
  Na  Na4  1  0.197  0.853  0.469  1.0
  Na  Na5  1  0.232  0.385  0.557  1.0
  Na  Na6  1  0.732  0.615  0.943  1.0
  Na  Na7  1  0.303  0.853  0.969  1.0
  V  V8  1  0.801  0.398  0.226  1.0
  V  V9  1  0.667  0.022  0.326  1.0
  V  V10  1  0.167  0.978  0.174  1.0
  V  V11  1  0.301  0.602  0.274  1.0
  V  V12  1  0.699  0.398  0.726  1.0
  V  V13  1  0.833  0.022  0.826  1.0
  V  V14  1  0.333  0.978  0.674  1.0
  V  V15  1  0.199  0.602  0.774  1.0
  O  O16  1  0.268  0.113  0.061  1.0
  O  O17  1  0.712  0.396  0.091  1.0
  O  O18  1  0.341  0.004  0.298  1.0
  O  O19  1  0.133  0.441  0.226  1.0
  O  O20  1  0.242  0.774  0.161  1.0
  O  O21  1  0.742  0.226  0.339  1.0
  O  O22  1  0.633  0.559  0.274  1.0
  O  O23  1  0.841  0.996  0.202  1.0
  O  O24  1  0.212  0.604  0.409  1.0
  O  O25  1  0.232  0.113  0.561  1.0
  O  O26  1  0.768  0.887  0.439  1.0
  O  O27  1  0.788  0.396  0.591  1.0
  O  O28  1  0.159  0.004  0.798  1.0
  O  O29  1  0.367  0.441  0.726  1.0
  O  O30  1  0.258  0.774  0.661  1.0
  O  O31  1  0.758  0.226  0.839  1.0
  O  O32  1  0.867  0.559  0.774  1.0
  O  O33  1  0.659  0.996  0.702  1.0
  O  O34  1  0.288  0.604  0.909  1.0
  O  O35  1  0.732  0.887  0.939  1.0
[/CIF]
.