The compound described by LuCe3Se6 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to two equivalent Se(3) and four equivalent Se(2) atoms to form LuSe6 octahedra that share edges with two equivalent Lu(1)Se6 octahedra and edges with four equivalent Ce(2)Se7 pentagonal bipyramids. In the second Lu site, Lu(2) is bonded to two equivalent Se(4) and four equivalent Se(1) atoms to form LuSe6 octahedra that share corners with two equivalent Ce(2)Se7 pentagonal bipyramids and edges with two equivalent Lu(2)Se6 octahedra. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 8-coordinate geometry to one Se(2), one Se(5), two equivalent Se(1), two equivalent Se(3), and two equivalent Se(6) atoms. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(4), one Se(6), two equivalent Se(3), and two equivalent Se(5) atoms to form distorted CeSe7 pentagonal bipyramids that share  a cornercorner with one Lu(2)Se6 octahedra, edges with two equivalent Lu(1)Se6 octahedra, and edges with two equivalent Ce(2)Se7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. In the third Ce site, Ce(3) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), two equivalent Se(4), two equivalent Se(5), and two equivalent Se(6) atoms. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Lu(2), one Ce(3), and two equivalent Ce(1) atoms to form distorted SeCe3Lu2 trigonal bipyramids that share corners with two equivalent Se(3)Ce4Lu square pyramids, corners with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with three equivalent Se(2)Ce3Lu2 trigonal bipyramids, corners with four equivalent Se(6)Ce5 trigonal bipyramids, corners with two equivalent Se(4)Ce3Lu trigonal pyramids,  an edgeedge with one Se(3)Ce4Lu square pyramid,  an edgeedge with one Se(6)Ce5 trigonal bipyramid, edges with three equivalent Se(1)Ce3Lu2 trigonal bipyramids, and edges with two equivalent Se(4)Ce3Lu trigonal pyramids. In the second Se site, Se(2) is bonded to two equivalent Lu(1), one Ce(1), one Ce(2), and one Ce(3) atom to form distorted SeCe3Lu2 trigonal bipyramids that share  a cornercorner with one Se(6)Ce5 trigonal bipyramid, corners with three equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with four equivalent Se(2)Ce3Lu2 trigonal bipyramids, corners with three equivalent Se(4)Ce3Lu trigonal pyramids, edges with four equivalent Se(3)Ce4Lu square pyramids,  an edgeedge with one Se(2)Ce3Lu2 trigonal bipyramid, and edges with two equivalent Se(6)Ce5 trigonal bipyramids. In the third Se site, Se(3) is bonded to one Lu(1), two equivalent Ce(1), and two equivalent Ce(2) atoms to form SeCe4Lu square pyramids that share  a cornercorner with one Se(3)Ce4Lu square pyramid, corners with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with four equivalent Se(6)Ce5 trigonal bipyramids, corners with two equivalent Se(4)Ce3Lu trigonal pyramids, edges with two equivalent Se(3)Ce4Lu square pyramids,  an edgeedge with one Se(1)Ce3Lu2 trigonal bipyramid,  an edgeedge with one Se(6)Ce5 trigonal bipyramid, and edges with four equivalent Se(2)Ce3Lu2 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to one Lu(2), one Ce(2), and two equivalent Ce(3) atoms to form distorted SeCe3Lu trigonal pyramids that share corners with two equivalent Se(3)Ce4Lu square pyramids, corners with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with two equivalent Se(6)Ce5 trigonal bipyramids, corners with three equivalent Se(2)Ce3Lu2 trigonal bipyramids, corners with three equivalent Se(4)Ce3Lu trigonal pyramids, edges with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, and  a faceface with one Se(6)Ce5 trigonal bipyramid. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to one Ce(1), two equivalent Ce(2), and two equivalent Ce(3) atoms. In the sixth Se site, Se(6) is bonded to one Ce(2), two equivalent Ce(1), and two equivalent Ce(3) atoms to form distorted SeCe5 trigonal bipyramids that share corners with four equivalent Se(3)Ce4Lu square pyramids,  a cornercorner with one Se(2)Ce3Lu2 trigonal bipyramid, corners with four equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with two equivalent Se(4)Ce3Lu trigonal pyramids,  an edgeedge with one Se(3)Ce4Lu square pyramid,  an edgeedge with one Se(1)Ce3Lu2 trigonal bipyramid, edges with two equivalent Se(2)Ce3Lu2 trigonal bipyramids, edges with two equivalent Se(6)Ce5 trigonal bipyramids, and  a faceface with one Se(4)Ce3Lu trigonal pyramid. is represented by the CIF card [CIF]
data_Ce3LuSe6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.101
_cell_length_b   14.522
_cell_length_c   17.572
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1046.432
_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
  Ce  Ce0  1  0.000  0.749  0.600  1.0
  Ce  Ce1  1  0.500  0.249  0.900  1.0
  Ce  Ce2  1  0.500  0.681  0.849  1.0
  Ce  Ce3  1  0.000  0.181  0.651  1.0
  Ce  Ce4  1  0.000  0.048  0.219  1.0
  Ce  Ce5  1  0.500  0.548  0.281  1.0
  Ce  Ce6  1  0.000  0.251  0.400  1.0
  Ce  Ce7  1  0.500  0.751  0.100  1.0
  Ce  Ce8  1  0.000  0.952  0.781  1.0
  Ce  Ce9  1  0.500  0.319  0.151  1.0
  Ce  Ce10  1  0.500  0.452  0.719  1.0
  Ce  Ce11  1  0.000  0.819  0.349  1.0
  Lu  Lu12  1  0.500  0.000  0.500  1.0
  Lu  Lu13  1  0.000  0.500  0.000  1.0
  Lu  Lu14  1  0.500  0.000  0.000  1.0
  Lu  Lu15  1  0.000  0.500  0.500  1.0
  Se  Se16  1  0.500  0.592  0.579  1.0
  Se  Se17  1  0.000  0.023  0.394  1.0
  Se  Se18  1  0.500  0.811  0.476  1.0
  Se  Se19  1  0.500  0.523  0.106  1.0
  Se  Se20  1  0.500  0.875  0.888  1.0
  Se  Se21  1  0.500  0.895  0.246  1.0
  Se  Se22  1  0.000  0.689  0.976  1.0
  Se  Se23  1  0.000  0.395  0.254  1.0
  Se  Se24  1  0.500  0.125  0.112  1.0
  Se  Se25  1  0.000  0.686  0.210  1.0
  Se  Se26  1  0.500  0.105  0.754  1.0
  Se  Se27  1  0.500  0.408  0.421  1.0
  Se  Se28  1  0.000  0.311  0.024  1.0
  Se  Se29  1  0.000  0.625  0.388  1.0
  Se  Se30  1  0.500  0.189  0.524  1.0
  Se  Se31  1  0.000  0.092  0.921  1.0
  Se  Se32  1  0.500  0.186  0.290  1.0
  Se  Se33  1  0.500  0.477  0.894  1.0
  Se  Se34  1  0.000  0.605  0.746  1.0
  Se  Se35  1  0.500  0.814  0.710  1.0
  Se  Se36  1  0.000  0.977  0.606  1.0
  Se  Se37  1  0.000  0.314  0.790  1.0
  Se  Se38  1  0.000  0.375  0.612  1.0
  Se  Se39  1  0.000  0.908  0.079  1.0
[/CIF]
.
The compound described by LuCe3Se6 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to two equivalent Se(3) and four equivalent Se(2) atoms to form LuSe6 octahedra that share edges with two equivalent Lu(1)Se6 octahedra and edges with four equivalent Ce(2)Se7 pentagonal bipyramids. In the second Lu site, Lu(2) is bonded to two equivalent Se(4) and four equivalent Se(1) atoms to form LuSe6 octahedra that share corners with two equivalent Ce(2)Se7 pentagonal bipyramids and edges with two equivalent Lu(2)Se6 octahedra. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 8-coordinate geometry to one Se(2), one Se(5), two equivalent Se(1), two equivalent Se(3), and two equivalent Se(6) atoms. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(4), one Se(6), two equivalent Se(3), and two equivalent Se(5) atoms to form distorted CeSe7 pentagonal bipyramids that share  a cornercorner with one Lu(2)Se6 octahedra, edges with two equivalent Lu(1)Se6 octahedra, and edges with two equivalent Ce(2)Se7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. In the third Ce site, Ce(3) is bonded in a 8-coordinate geometry to one Se(1), one Se(2), two equivalent Se(4), two equivalent Se(5), and two equivalent Se(6) atoms. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Lu(2), one Ce(3), and two equivalent Ce(1) atoms to form distorted SeCe3Lu2 trigonal bipyramids that share corners with two equivalent Se(3)Ce4Lu square pyramids, corners with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with three equivalent Se(2)Ce3Lu2 trigonal bipyramids, corners with four equivalent Se(6)Ce5 trigonal bipyramids, corners with two equivalent Se(4)Ce3Lu trigonal pyramids,  an edgeedge with one Se(3)Ce4Lu square pyramid,  an edgeedge with one Se(6)Ce5 trigonal bipyramid, edges with three equivalent Se(1)Ce3Lu2 trigonal bipyramids, and edges with two equivalent Se(4)Ce3Lu trigonal pyramids. In the second Se site, Se(2) is bonded to two equivalent Lu(1), one Ce(1), one Ce(2), and one Ce(3) atom to form distorted SeCe3Lu2 trigonal bipyramids that share  a cornercorner with one Se(6)Ce5 trigonal bipyramid, corners with three equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with four equivalent Se(2)Ce3Lu2 trigonal bipyramids, corners with three equivalent Se(4)Ce3Lu trigonal pyramids, edges with four equivalent Se(3)Ce4Lu square pyramids,  an edgeedge with one Se(2)Ce3Lu2 trigonal bipyramid, and edges with two equivalent Se(6)Ce5 trigonal bipyramids. In the third Se site, Se(3) is bonded to one Lu(1), two equivalent Ce(1), and two equivalent Ce(2) atoms to form SeCe4Lu square pyramids that share  a cornercorner with one Se(3)Ce4Lu square pyramid, corners with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with four equivalent Se(6)Ce5 trigonal bipyramids, corners with two equivalent Se(4)Ce3Lu trigonal pyramids, edges with two equivalent Se(3)Ce4Lu square pyramids,  an edgeedge with one Se(1)Ce3Lu2 trigonal bipyramid,  an edgeedge with one Se(6)Ce5 trigonal bipyramid, and edges with four equivalent Se(2)Ce3Lu2 trigonal bipyramids. In the fourth Se site, Se(4) is bonded to one Lu(2), one Ce(2), and two equivalent Ce(3) atoms to form distorted SeCe3Lu trigonal pyramids that share corners with two equivalent Se(3)Ce4Lu square pyramids, corners with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with two equivalent Se(6)Ce5 trigonal bipyramids, corners with three equivalent Se(2)Ce3Lu2 trigonal bipyramids, corners with three equivalent Se(4)Ce3Lu trigonal pyramids, edges with two equivalent Se(1)Ce3Lu2 trigonal bipyramids, and  a faceface with one Se(6)Ce5 trigonal bipyramid. In the fifth Se site, Se(5) is bonded in a 5-coordinate geometry to one Ce(1), two equivalent Ce(2), and two equivalent Ce(3) atoms. In the sixth Se site, Se(6) is bonded to one Ce(2), two equivalent Ce(1), and two equivalent Ce(3) atoms to form distorted SeCe5 trigonal bipyramids that share corners with four equivalent Se(3)Ce4Lu square pyramids,  a cornercorner with one Se(2)Ce3Lu2 trigonal bipyramid, corners with four equivalent Se(1)Ce3Lu2 trigonal bipyramids, corners with two equivalent Se(4)Ce3Lu trigonal pyramids,  an edgeedge with one Se(3)Ce4Lu square pyramid,  an edgeedge with one Se(1)Ce3Lu2 trigonal bipyramid, edges with two equivalent Se(2)Ce3Lu2 trigonal bipyramids, edges with two equivalent Se(6)Ce5 trigonal bipyramids, and  a faceface with one Se(4)Ce3Lu trigonal pyramid. is represented by the CIF card [CIF]
data_Ce3LuSe6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.101
_cell_length_b   14.522
_cell_length_c   17.572
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1046.432
_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
  Ce  Ce0  1  0.000  0.749  0.600  1.0
  Ce  Ce1  1  0.500  0.249  0.900  1.0
  Ce  Ce2  1  0.500  0.681  0.849  1.0
  Ce  Ce3  1  0.000  0.181  0.651  1.0
  Ce  Ce4  1  0.000  0.048  0.219  1.0
  Ce  Ce5  1  0.500  0.548  0.281  1.0
  Ce  Ce6  1  0.000  0.251  0.400  1.0
  Ce  Ce7  1  0.500  0.751  0.100  1.0
  Ce  Ce8  1  0.000  0.952  0.781  1.0
  Ce  Ce9  1  0.500  0.319  0.151  1.0
  Ce  Ce10  1  0.500  0.452  0.719  1.0
  Ce  Ce11  1  0.000  0.819  0.349  1.0
  Lu  Lu12  1  0.500  0.000  0.500  1.0
  Lu  Lu13  1  0.000  0.500  0.000  1.0
  Lu  Lu14  1  0.500  0.000  0.000  1.0
  Lu  Lu15  1  0.000  0.500  0.500  1.0
  Se  Se16  1  0.500  0.592  0.579  1.0
  Se  Se17  1  0.000  0.023  0.394  1.0
  Se  Se18  1  0.500  0.811  0.476  1.0
  Se  Se19  1  0.500  0.523  0.106  1.0
  Se  Se20  1  0.500  0.875  0.888  1.0
  Se  Se21  1  0.500  0.895  0.246  1.0
  Se  Se22  1  0.000  0.689  0.976  1.0
  Se  Se23  1  0.000  0.395  0.254  1.0
  Se  Se24  1  0.500  0.125  0.112  1.0
  Se  Se25  1  0.000  0.686  0.210  1.0
  Se  Se26  1  0.500  0.105  0.754  1.0
  Se  Se27  1  0.500  0.408  0.421  1.0
  Se  Se28  1  0.000  0.311  0.024  1.0
  Se  Se29  1  0.000  0.625  0.388  1.0
  Se  Se30  1  0.500  0.189  0.524  1.0
  Se  Se31  1  0.000  0.092  0.921  1.0
  Se  Se32  1  0.500  0.186  0.290  1.0
  Se  Se33  1  0.500  0.477  0.894  1.0
  Se  Se34  1  0.000  0.605  0.746  1.0
  Se  Se35  1  0.500  0.814  0.710  1.0
  Se  Se36  1  0.000  0.977  0.606  1.0
  Se  Se37  1  0.000  0.314  0.790  1.0
  Se  Se38  1  0.000  0.375  0.612  1.0
  Se  Se39  1  0.000  0.908  0.079  1.0
[/CIF]
.