data_Na2WSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.95
_cell_length_b   4.95
_cell_length_c   4.95
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2WSe
_chemical_formula_sum   'Na2 W1 Se1'
_cell_volume   85.95
_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  0.0  0.0  0.0  1.0
  Na  Na1  1  0.75  0.75  0.75  1.0
  W  W3  1  0.25  0.25  0.25  1.0
  Se  Se2  1  0.5  0.5  0.5  1.0

data_Na2WSe
_symmetry_space_group_name_H-M   F-43m
_cell_length_a   7.01
_cell_length_b   7.01
_cell_length_c   7.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   216
_chemical_formula_structural   Na2WSe
_chemical_formula_sum   'Na8 W4 Se4'
_cell_volume   343.8
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'y, -x, -z'
  3  '-x, -y, z'
  4  '-y, x, -z'
  5  'x, -y, -z'
  6  'y, x, z'
  7  '-x, y, -z'
  8  '-y, -x, z'
  9  'z, x, y'
  10  '-z, y, -x'
  11  'z, -x, -y'
  12  '-z, -y, x'
  13  '-z, x, -y'
  14  'z, y, x'
  15  '-z, -x, y'
  16  'z, -y, -x'
  17  'y, z, x'
  18  '-x, -z, y'
  19  '-y, z, -x'
  20  'x, -z, -y'
  21  '-y, -z, x'
  22  'x, z, y'
  23  'y, -z, -x'
  24  '-x, z, -y'
  25  'x+1/2, y+1/2, z'
  26  'y+1/2, -x+1/2, -z'
  27  '-x+1/2, -y+1/2, z'
  28  '-y+1/2, x+1/2, -z'
  29  'x+1/2, -y+1/2, -z'
  30  'y+1/2, x+1/2, z'
  31  '-x+1/2, y+1/2, -z'
  32  '-y+1/2, -x+1/2, z'
  33  'z+1/2, x+1/2, y'
  34  '-z+1/2, y+1/2, -x'
  35  'z+1/2, -x+1/2, -y'
  36  '-z+1/2, -y+1/2, x'
  37  '-z+1/2, x+1/2, -y'
  38  'z+1/2, y+1/2, x'
  39  '-z+1/2, -x+1/2, y'
  40  'z+1/2, -y+1/2, -x'
  41  'y+1/2, z+1/2, x'
  42  '-x+1/2, -z+1/2, y'
  43  '-y+1/2, z+1/2, -x'
  44  'x+1/2, -z+1/2, -y'
  45  '-y+1/2, -z+1/2, x'
  46  'x+1/2, z+1/2, y'
  47  'y+1/2, -z+1/2, -x'
  48  '-x+1/2, z+1/2, -y'
  49  'x+1/2, y, z+1/2'
  50  'y+1/2, -x, -z+1/2'
  51  '-x+1/2, -y, z+1/2'
  52  '-y+1/2, x, -z+1/2'
  53  'x+1/2, -y, -z+1/2'
  54  'y+1/2, x, z+1/2'
  55  '-x+1/2, y, -z+1/2'
  56  '-y+1/2, -x, z+1/2'
  57  'z+1/2, x, y+1/2'
  58  '-z+1/2, y, -x+1/2'
  59  'z+1/2, -x, -y+1/2'
  60  '-z+1/2, -y, x+1/2'
  61  '-z+1/2, x, -y+1/2'
  62  'z+1/2, y, x+1/2'
  63  '-z+1/2, -x, y+1/2'
  64  'z+1/2, -y, -x+1/2'
  65  'y+1/2, z, x+1/2'
  66  '-x+1/2, -z, y+1/2'
  67  '-y+1/2, z, -x+1/2'
  68  'x+1/2, -z, -y+1/2'
  69  '-y+1/2, -z, x+1/2'
  70  'x+1/2, z, y+1/2'
  71  'y+1/2, -z, -x+1/2'
  72  '-x+1/2, z, -y+1/2'
  73  'x, y+1/2, z+1/2'
  74  'y, -x+1/2, -z+1/2'
  75  '-x, -y+1/2, z+1/2'
  76  '-y, x+1/2, -z+1/2'
  77  'x, -y+1/2, -z+1/2'
  78  'y, x+1/2, z+1/2'
  79  '-x, y+1/2, -z+1/2'
  80  '-y, -x+1/2, z+1/2'
  81  'z, x+1/2, y+1/2'
  82  '-z, y+1/2, -x+1/2'
  83  'z, -x+1/2, -y+1/2'
  84  '-z, -y+1/2, x+1/2'
  85  '-z, x+1/2, -y+1/2'
  86  'z, y+1/2, x+1/2'
  87  '-z, -x+1/2, y+1/2'
  88  'z, -y+1/2, -x+1/2'
  89  'y, z+1/2, x+1/2'
  90  '-x, -z+1/2, y+1/2'
  91  '-y, z+1/2, -x+1/2'
  92  'x, -z+1/2, -y+1/2'
  93  '-y, -z+1/2, x+1/2'
  94  'x, z+1/2, y+1/2'
  95  'y, -z+1/2, -x+1/2'
  96  '-x, z+1/2, -y+1/2'
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  4  0.0  0.0  0.0  1.0
  Na  Na1  4  0.25  0.25  0.25  1.0
  W  W2  4  0.25  0.25  0.75  1.0
  Se  Se3  4  0.0  0.0  0.5  1.0

Na Na W Se
Na Na W Se 0 1 - - - 0 1 - - o 0 1 o - - 0 1 - o - 0 3 - - o 0 3 - o - 0 3 - o o 0 3 o - - 0 3 o - o 0 3 o o - 0 2 - o o 0 2 o - o 0 2 o o - 0 2 o o o 1 3 o o o 1 3 o o + 1 3 + o o 1 3 o + o 1 2 o o + 1 2 o + o 1 2 o + + 1 2 + o o 1 2 + o + 1 2 + + o 2 3 o - o 2 3 - o o 2 3 o o - 2 3 o o o 
Na2WSe is Zintl Phase-derived structured and crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to four equivalent W(1) atoms to form distorted NaW4 tetrahedra that share corners with twelve equivalent Na(1)W4 tetrahedra, corners with twelve equivalent Na(2)W6Se4 tetrahedra, and faces with four equivalent Na(2)W6Se4 tetrahedra. There are three shorter (3.02 Å) and one longer (3.08 Å) Na(1)-W(1) bond length. In the second Na site, Na(2) is bonded to six equivalent W(1) and four equivalent Se(1) atoms to form distorted NaW6Se4 tetrahedra that share corners with six equivalent Na(2)W6Se4 tetrahedra, corners with twelve equivalent Na(1)W4 tetrahedra, faces with four equivalent Na(1)W4 tetrahedra, and faces with twelve equivalent Na(2)W6Se4 tetrahedra. There are three shorter (3.48 Å) and three longer (3.52 Å) Na(2)-W(1) bond lengths. There is one shorter (3.02 Å) and three longer (3.04 Å) Na(2)-Se(1) bond lengths. W(1) is bonded in a 14-coordinate geometry to four equivalent Na(1), six equivalent Na(2), and four equivalent Se(1) atoms. There is one shorter (3.02 Å) and three longer (3.04 Å) W(1)-Se(1) bond lengths. Se(1) is bonded in a 4-coordinate geometry to four equivalent Na(2) and four equivalent W(1) atoms.