The structure described by Ba4UCr2S9 crystallizes in the trigonal P321 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one S(4), two equivalent S(1), two equivalent S(2), two equivalent S(3), and two equivalent S(5) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent S(3), two equivalent S(4), two equivalent S(5), and four equivalent S(2) atoms. In the third Ba site, Ba(3) is bonded in a 8-coordinate geometry to two equivalent S(3), two equivalent S(5), and four equivalent S(1) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form distorted US6 pentagonal pyramids that share  a faceface with one Cr(1)S6 octahedra and  a faceface with one Cr(3)S6 octahedra. In the second U site, U(2) is bonded to six equivalent S(5) atoms to form distorted US6 pentagonal pyramids that share faces with two equivalent Cr(2)S6 octahedra. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent S(1) and three equivalent S(3) atoms to form CrS6 octahedra that share  a faceface with one Cr(3)S6 octahedra and  a faceface with one U(1)S6 pentagonal pyramid. In the second Cr site, Cr(2) is bonded to three equivalent S(4) and three equivalent S(5) atoms to form CrS6 octahedra that share  a faceface with one Cr(2)S6 octahedra and  a faceface with one U(2)S6 pentagonal pyramid. In the third Cr site, Cr(3) is bonded to three equivalent S(2) and three equivalent S(3) atoms to form CrS6 octahedra that share  a faceface with one Cr(1)S6 octahedra and  a faceface with one U(1)S6 pentagonal pyramid. There are five inequivalent S sites. In the first S site, S(5) is bonded to one Ba(2), one Ba(3), two equivalent Ba(1), one U(2), and one Cr(2) atom to form distorted SBa4UCr octahedra that share  a cornercorner with one S(4)Ba4Cr2 octahedra, corners with three equivalent S(5)Ba4UCr octahedra, corners with four equivalent S(1)Ba4UCr octahedra, corners with five equivalent S(3)Ba4Cr2 octahedra,  an edgeedge with one S(5)Ba4UCr octahedra, edges with two equivalent S(1)Ba4UCr octahedra,  a faceface with one S(3)Ba4Cr2 octahedra, faces with two equivalent S(4)Ba4Cr2 octahedra, and faces with two equivalent S(5)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 5-70°. In the second S site, S(1) is bonded to two equivalent Ba(1), two equivalent Ba(3), one U(1), and one Cr(1) atom to form distorted SBa4UCr octahedra that share corners with two equivalent S(4)Ba4Cr2 octahedra, corners with three equivalent S(3)Ba4Cr2 octahedra, corners with three equivalent S(1)Ba4UCr octahedra, corners with four equivalent S(5)Ba4UCr octahedra,  an edgeedge with one S(3)Ba4Cr2 octahedra, edges with two equivalent S(5)Ba4UCr octahedra, faces with two equivalent S(3)Ba4Cr2 octahedra, and faces with three equivalent S(1)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 2-70°. In the third S site, S(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), one U(1), and one Cr(3) atom. In the fourth S site, S(3) is bonded to one Ba(2), one Ba(3), two equivalent Ba(1), one Cr(1), and one Cr(3) atom to form SBa4Cr2 octahedra that share corners with two equivalent S(3)Ba4Cr2 octahedra, corners with two equivalent S(4)Ba4Cr2 octahedra, corners with three equivalent S(1)Ba4UCr octahedra, corners with five equivalent S(5)Ba4UCr octahedra,  an edgeedge with one S(4)Ba4Cr2 octahedra,  an edgeedge with one S(1)Ba4UCr octahedra,  a faceface with one S(5)Ba4UCr octahedra, faces with two equivalent S(3)Ba4Cr2 octahedra, and faces with two equivalent S(1)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 2-63°. In the fifth S site, S(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Cr(2) atoms to form distorted SBa4Cr2 octahedra that share corners with two equivalent S(5)Ba4UCr octahedra, corners with four equivalent S(3)Ba4Cr2 octahedra, corners with four equivalent S(1)Ba4UCr octahedra, edges with two equivalent S(3)Ba4Cr2 octahedra, faces with two equivalent S(4)Ba4Cr2 octahedra, and faces with four equivalent S(5)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 5-56°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba4UCr2S9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.079
_cell_length_b   12.079
_cell_length_c   9.663
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1220.994
_cell_formula_units_Z   3
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  0.957  0.297  0.750  1.0
  Ba  Ba1  1  0.000  0.681  0.000  1.0
  Ba  Ba2  1  0.681  0.000  0.000  1.0
  Ba  Ba3  1  0.297  0.957  0.250  1.0
  Ba  Ba4  1  0.703  0.660  0.750  1.0
  Ba  Ba5  1  0.660  0.703  0.250  1.0
  Ba  Ba6  1  0.375  0.375  0.500  1.0
  Ba  Ba7  1  0.043  0.340  0.250  1.0
  Ba  Ba8  1  0.319  0.319  0.000  1.0
  Ba  Ba9  1  0.340  0.043  0.750  1.0
  Ba  Ba10  1  0.625  0.000  0.500  1.0
  Ba  Ba11  1  0.000  0.625  0.500  1.0
  U  U12  1  0.333  0.667  0.744  1.0
  U  U13  1  0.667  0.333  0.256  1.0
  U  U14  1  0.000  0.000  0.500  1.0
  Cr  Cr15  1  0.333  0.667  0.398  1.0
  Cr  Cr16  1  0.667  0.333  0.602  1.0
  Cr  Cr17  1  0.000  0.000  0.159  1.0
  Cr  Cr18  1  0.333  0.667  0.082  1.0
  Cr  Cr19  1  0.667  0.333  0.918  1.0
  Cr  Cr20  1  0.000  0.000  0.841  1.0
  S  S21  1  0.506  0.687  0.550  1.0
  S  S22  1  0.320  0.821  0.933  1.0
  S  S23  1  0.647  0.165  0.761  1.0
  S  S24  1  0.687  0.506  0.450  1.0
  S  S25  1  0.847  0.847  0.000  1.0
  S  S26  1  0.680  0.501  0.067  1.0
  S  S27  1  0.313  0.819  0.550  1.0
  S  S28  1  0.153  0.000  0.000  1.0
  S  S29  1  0.179  0.499  0.933  1.0
  S  S30  1  0.821  0.320  0.067  1.0
  S  S31  1  0.181  0.494  0.550  1.0
  S  S32  1  0.482  0.835  0.239  1.0
  S  S33  1  0.494  0.181  0.450  1.0
  S  S34  1  0.165  0.647  0.239  1.0
  S  S35  1  0.830  0.986  0.690  1.0
  S  S36  1  0.499  0.179  0.067  1.0
  S  S37  1  0.000  0.153  0.000  1.0
  S  S38  1  0.014  0.844  0.690  1.0
  S  S39  1  0.501  0.680  0.933  1.0
  S  S40  1  0.353  0.518  0.239  1.0
  S  S41  1  0.170  0.156  0.310  1.0
  S  S42  1  0.844  0.014  0.310  1.0
  S  S43  1  0.156  0.170  0.690  1.0
  S  S44  1  0.518  0.353  0.761  1.0
  S  S45  1  0.835  0.482  0.761  1.0
  S  S46  1  0.986  0.830  0.310  1.0
  S  S47  1  0.819  0.313  0.450  1.0
[/CIF]
.
The structure described by Ba4UCr2S9 crystallizes in the trigonal P321 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one S(4), two equivalent S(1), two equivalent S(2), two equivalent S(3), and two equivalent S(5) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent S(3), two equivalent S(4), two equivalent S(5), and four equivalent S(2) atoms. In the third Ba site, Ba(3) is bonded in a 8-coordinate geometry to two equivalent S(3), two equivalent S(5), and four equivalent S(1) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form distorted US6 pentagonal pyramids that share  a faceface with one Cr(1)S6 octahedra and  a faceface with one Cr(3)S6 octahedra. In the second U site, U(2) is bonded to six equivalent S(5) atoms to form distorted US6 pentagonal pyramids that share faces with two equivalent Cr(2)S6 octahedra. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent S(1) and three equivalent S(3) atoms to form CrS6 octahedra that share  a faceface with one Cr(3)S6 octahedra and  a faceface with one U(1)S6 pentagonal pyramid. In the second Cr site, Cr(2) is bonded to three equivalent S(4) and three equivalent S(5) atoms to form CrS6 octahedra that share  a faceface with one Cr(2)S6 octahedra and  a faceface with one U(2)S6 pentagonal pyramid. In the third Cr site, Cr(3) is bonded to three equivalent S(2) and three equivalent S(3) atoms to form CrS6 octahedra that share  a faceface with one Cr(1)S6 octahedra and  a faceface with one U(1)S6 pentagonal pyramid. There are five inequivalent S sites. In the first S site, S(5) is bonded to one Ba(2), one Ba(3), two equivalent Ba(1), one U(2), and one Cr(2) atom to form distorted SBa4UCr octahedra that share  a cornercorner with one S(4)Ba4Cr2 octahedra, corners with three equivalent S(5)Ba4UCr octahedra, corners with four equivalent S(1)Ba4UCr octahedra, corners with five equivalent S(3)Ba4Cr2 octahedra,  an edgeedge with one S(5)Ba4UCr octahedra, edges with two equivalent S(1)Ba4UCr octahedra,  a faceface with one S(3)Ba4Cr2 octahedra, faces with two equivalent S(4)Ba4Cr2 octahedra, and faces with two equivalent S(5)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 5-70°. In the second S site, S(1) is bonded to two equivalent Ba(1), two equivalent Ba(3), one U(1), and one Cr(1) atom to form distorted SBa4UCr octahedra that share corners with two equivalent S(4)Ba4Cr2 octahedra, corners with three equivalent S(3)Ba4Cr2 octahedra, corners with three equivalent S(1)Ba4UCr octahedra, corners with four equivalent S(5)Ba4UCr octahedra,  an edgeedge with one S(3)Ba4Cr2 octahedra, edges with two equivalent S(5)Ba4UCr octahedra, faces with two equivalent S(3)Ba4Cr2 octahedra, and faces with three equivalent S(1)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 2-70°. In the third S site, S(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), one U(1), and one Cr(3) atom. In the fourth S site, S(3) is bonded to one Ba(2), one Ba(3), two equivalent Ba(1), one Cr(1), and one Cr(3) atom to form SBa4Cr2 octahedra that share corners with two equivalent S(3)Ba4Cr2 octahedra, corners with two equivalent S(4)Ba4Cr2 octahedra, corners with three equivalent S(1)Ba4UCr octahedra, corners with five equivalent S(5)Ba4UCr octahedra,  an edgeedge with one S(4)Ba4Cr2 octahedra,  an edgeedge with one S(1)Ba4UCr octahedra,  a faceface with one S(5)Ba4UCr octahedra, faces with two equivalent S(3)Ba4Cr2 octahedra, and faces with two equivalent S(1)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 2-63°. In the fifth S site, S(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Cr(2) atoms to form distorted SBa4Cr2 octahedra that share corners with two equivalent S(5)Ba4UCr octahedra, corners with four equivalent S(3)Ba4Cr2 octahedra, corners with four equivalent S(1)Ba4UCr octahedra, edges with two equivalent S(3)Ba4Cr2 octahedra, faces with two equivalent S(4)Ba4Cr2 octahedra, and faces with four equivalent S(5)Ba4UCr octahedra. The corner-sharing octahedral tilt angles range from 5-56°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba4UCr2S9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.079
_cell_length_b   12.079
_cell_length_c   9.663
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1220.994
_cell_formula_units_Z   3
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  0.957  0.297  0.750  1.0
  Ba  Ba1  1  0.000  0.681  0.000  1.0
  Ba  Ba2  1  0.681  0.000  0.000  1.0
  Ba  Ba3  1  0.297  0.957  0.250  1.0
  Ba  Ba4  1  0.703  0.660  0.750  1.0
  Ba  Ba5  1  0.660  0.703  0.250  1.0
  Ba  Ba6  1  0.375  0.375  0.500  1.0
  Ba  Ba7  1  0.043  0.340  0.250  1.0
  Ba  Ba8  1  0.319  0.319  0.000  1.0
  Ba  Ba9  1  0.340  0.043  0.750  1.0
  Ba  Ba10  1  0.625  0.000  0.500  1.0
  Ba  Ba11  1  0.000  0.625  0.500  1.0
  U  U12  1  0.333  0.667  0.744  1.0
  U  U13  1  0.667  0.333  0.256  1.0
  U  U14  1  0.000  0.000  0.500  1.0
  Cr  Cr15  1  0.333  0.667  0.398  1.0
  Cr  Cr16  1  0.667  0.333  0.602  1.0
  Cr  Cr17  1  0.000  0.000  0.159  1.0
  Cr  Cr18  1  0.333  0.667  0.082  1.0
  Cr  Cr19  1  0.667  0.333  0.918  1.0
  Cr  Cr20  1  0.000  0.000  0.841  1.0
  S  S21  1  0.506  0.687  0.550  1.0
  S  S22  1  0.320  0.821  0.933  1.0
  S  S23  1  0.647  0.165  0.761  1.0
  S  S24  1  0.687  0.506  0.450  1.0
  S  S25  1  0.847  0.847  0.000  1.0
  S  S26  1  0.680  0.501  0.067  1.0
  S  S27  1  0.313  0.819  0.550  1.0
  S  S28  1  0.153  0.000  0.000  1.0
  S  S29  1  0.179  0.499  0.933  1.0
  S  S30  1  0.821  0.320  0.067  1.0
  S  S31  1  0.181  0.494  0.550  1.0
  S  S32  1  0.482  0.835  0.239  1.0
  S  S33  1  0.494  0.181  0.450  1.0
  S  S34  1  0.165  0.647  0.239  1.0
  S  S35  1  0.830  0.986  0.690  1.0
  S  S36  1  0.499  0.179  0.067  1.0
  S  S37  1  0.000  0.153  0.000  1.0
  S  S38  1  0.014  0.844  0.690  1.0
  S  S39  1  0.501  0.680  0.933  1.0
  S  S40  1  0.353  0.518  0.239  1.0
  S  S41  1  0.170  0.156  0.310  1.0
  S  S42  1  0.844  0.014  0.310  1.0
  S  S43  1  0.156  0.170  0.690  1.0
  S  S44  1  0.518  0.353  0.761  1.0
  S  S45  1  0.835  0.482  0.761  1.0
  S  S46  1  0.986  0.830  0.310  1.0
  S  S47  1  0.819  0.313  0.450  1.0
[/CIF]
.