The crystal structure described by Ba4(NbSe4)3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one Se(1), three equivalent Se(2), four equivalent Se(3), and four equivalent Se(4) atoms to form BaSe12 cuboctahedra that share corners with two equivalent Ba(1)Se12 cuboctahedra, corners with four equivalent Ba(2)Se12 cuboctahedra, corners with two equivalent Nb(1)Se6 octahedra, corners with three equivalent Nb(2)Se6 octahedra, faces with three equivalent Ba(1)Se12 cuboctahedra, faces with five equivalent Ba(2)Se12 cuboctahedra,  a faceface with one Nb(1)Se6 octahedra, and faces with three equivalent Nb(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 14-29°. In the second Ba site, Ba(2) is bonded to one Se(2), three equivalent Se(1), four equivalent Se(3), and four equivalent Se(4) atoms to form BaSe12 cuboctahedra that share corners with two equivalent Ba(2)Se12 cuboctahedra, corners with four equivalent Ba(1)Se12 cuboctahedra,  a cornercorner with one Nb(1)Se6 octahedra, corners with three equivalent Nb(2)Se6 octahedra, faces with three equivalent Ba(2)Se12 cuboctahedra, faces with five equivalent Ba(1)Se12 cuboctahedra, faces with two equivalent Nb(1)Se6 octahedra, and faces with three equivalent Nb(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 16-31°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent Se(1) and four equivalent Se(4) atoms to form NbSe6 octahedra that share corners with two equivalent Ba(2)Se12 cuboctahedra, corners with four equivalent Ba(1)Se12 cuboctahedra, faces with two equivalent Ba(1)Se12 cuboctahedra, faces with four equivalent Ba(2)Se12 cuboctahedra, and faces with two equivalent Nb(2)Se6 octahedra. In the second Nb site, Nb(2) is bonded to one Se(1), one Se(2), two equivalent Se(3), and two equivalent Se(4) atoms to form distorted NbSe6 octahedra that share corners with three equivalent Ba(1)Se12 cuboctahedra, corners with three equivalent Ba(2)Se12 cuboctahedra, faces with three equivalent Ba(1)Se12 cuboctahedra, faces with three equivalent Ba(2)Se12 cuboctahedra, and  a faceface with one Nb(1)Se6 octahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ba(1), three equivalent Ba(2), one Nb(1), and one Nb(2) atom to form a mixture of distorted edge, face, and corner-sharing SeBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-64°. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Nb(2) atom. In the third Se site, Se(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1), two equivalent Ba(2), and one Nb(2) atom. In the fourth Se site, Se(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), one Nb(1), and one Nb(2) atom to form a mixture of distorted edge, face, and corner-sharing SeBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-64°. is represented by the CIF file [CIF]
data_Ba4(NbSe4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.407
_cell_length_b   9.407
_cell_length_c   12.124
_cell_angle_alpha   50.105
_cell_angle_beta   50.105
_cell_angle_gamma   43.661
_symmetry_Int_Tables_number   1
_cell_volume   535.466
_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
  Ba  Ba0  1  0.334  0.334  0.791  1.0
  Ba  Ba1  1  0.332  0.332  0.299  1.0
  Ba  Ba2  1  0.668  0.668  0.701  1.0
  Ba  Ba3  1  0.666  0.666  0.209  1.0
  Nb  Nb4  1  0.000  0.000  0.000  1.0
  Nb  Nb5  1  0.999  0.999  0.720  1.0
  Nb  Nb6  1  0.001  0.001  0.280  1.0
  Se  Se7  1  0.166  0.166  0.707  1.0
  Se  Se8  1  0.175  0.175  0.196  1.0
  Se  Se9  1  0.178  0.647  0.463  1.0
  Se  Se10  1  0.176  0.658  0.955  1.0
  Se  Se11  1  0.647  0.178  0.463  1.0
  Se  Se12  1  0.658  0.176  0.955  1.0
  Se  Se13  1  0.825  0.825  0.804  1.0
  Se  Se14  1  0.834  0.834  0.293  1.0
  Se  Se15  1  0.824  0.342  0.045  1.0
  Se  Se16  1  0.822  0.353  0.537  1.0
  Se  Se17  1  0.342  0.824  0.045  1.0
  Se  Se18  1  0.353  0.822  0.537  1.0
[/CIF]
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The crystal structure described by Ba4(NbSe4)3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one Se(1), three equivalent Se(2), four equivalent Se(3), and four equivalent Se(4) atoms to form BaSe12 cuboctahedra that share corners with two equivalent Ba(1)Se12 cuboctahedra, corners with four equivalent Ba(2)Se12 cuboctahedra, corners with two equivalent Nb(1)Se6 octahedra, corners with three equivalent Nb(2)Se6 octahedra, faces with three equivalent Ba(1)Se12 cuboctahedra, faces with five equivalent Ba(2)Se12 cuboctahedra,  a faceface with one Nb(1)Se6 octahedra, and faces with three equivalent Nb(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 14-29°. In the second Ba site, Ba(2) is bonded to one Se(2), three equivalent Se(1), four equivalent Se(3), and four equivalent Se(4) atoms to form BaSe12 cuboctahedra that share corners with two equivalent Ba(2)Se12 cuboctahedra, corners with four equivalent Ba(1)Se12 cuboctahedra,  a cornercorner with one Nb(1)Se6 octahedra, corners with three equivalent Nb(2)Se6 octahedra, faces with three equivalent Ba(2)Se12 cuboctahedra, faces with five equivalent Ba(1)Se12 cuboctahedra, faces with two equivalent Nb(1)Se6 octahedra, and faces with three equivalent Nb(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 16-31°. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent Se(1) and four equivalent Se(4) atoms to form NbSe6 octahedra that share corners with two equivalent Ba(2)Se12 cuboctahedra, corners with four equivalent Ba(1)Se12 cuboctahedra, faces with two equivalent Ba(1)Se12 cuboctahedra, faces with four equivalent Ba(2)Se12 cuboctahedra, and faces with two equivalent Nb(2)Se6 octahedra. In the second Nb site, Nb(2) is bonded to one Se(1), one Se(2), two equivalent Se(3), and two equivalent Se(4) atoms to form distorted NbSe6 octahedra that share corners with three equivalent Ba(1)Se12 cuboctahedra, corners with three equivalent Ba(2)Se12 cuboctahedra, faces with three equivalent Ba(1)Se12 cuboctahedra, faces with three equivalent Ba(2)Se12 cuboctahedra, and  a faceface with one Nb(1)Se6 octahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ba(1), three equivalent Ba(2), one Nb(1), and one Nb(2) atom to form a mixture of distorted edge, face, and corner-sharing SeBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-64°. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one Nb(2) atom. In the third Se site, Se(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1), two equivalent Ba(2), and one Nb(2) atom. In the fourth Se site, Se(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), one Nb(1), and one Nb(2) atom to form a mixture of distorted edge, face, and corner-sharing SeBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-64°. is represented by the CIF file [CIF]
data_Ba4(NbSe4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.407
_cell_length_b   9.407
_cell_length_c   12.124
_cell_angle_alpha   50.105
_cell_angle_beta   50.105
_cell_angle_gamma   43.661
_symmetry_Int_Tables_number   1
_cell_volume   535.466
_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
  Ba  Ba0  1  0.334  0.334  0.791  1.0
  Ba  Ba1  1  0.332  0.332  0.299  1.0
  Ba  Ba2  1  0.668  0.668  0.701  1.0
  Ba  Ba3  1  0.666  0.666  0.209  1.0
  Nb  Nb4  1  0.000  0.000  0.000  1.0
  Nb  Nb5  1  0.999  0.999  0.720  1.0
  Nb  Nb6  1  0.001  0.001  0.280  1.0
  Se  Se7  1  0.166  0.166  0.707  1.0
  Se  Se8  1  0.175  0.175  0.196  1.0
  Se  Se9  1  0.178  0.647  0.463  1.0
  Se  Se10  1  0.176  0.658  0.955  1.0
  Se  Se11  1  0.647  0.178  0.463  1.0
  Se  Se12  1  0.658  0.176  0.955  1.0
  Se  Se13  1  0.825  0.825  0.804  1.0
  Se  Se14  1  0.834  0.834  0.293  1.0
  Se  Se15  1  0.824  0.342  0.045  1.0
  Se  Se16  1  0.822  0.353  0.537  1.0
  Se  Se17  1  0.342  0.824  0.045  1.0
  Se  Se18  1  0.353  0.822  0.537  1.0
[/CIF]
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