The structure described by Ce6Ni20As13 crystallizes in the hexagonal P-6 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 16-coordinate geometry to one Ni(1), one Ni(8), two equivalent Ni(2), two equivalent Ni(5), two equivalent Ni(6), two equivalent Ni(7), two equivalent As(2), and four equivalent As(1) atoms. In the second Ce site, Ce(2) is bonded in a 15-coordinate geometry to one Ni(6), two equivalent Ni(4), two equivalent Ni(5), two equivalent Ni(7), two equivalent Ni(8), two equivalent As(4), and four equivalent As(3) atoms. There are eight inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Ce(1), one As(4), one As(5), and two equivalent As(2) atoms to form distorted NiCeAs4 tetrahedra that share  a cornercorner with one Ni(5)Ce4As4 tetrahedra, corners with four equivalent Ni(1)CeAs4 tetrahedra,  an edgeedge with one Ni(5)Ce4As4 tetrahedra, edges with two equivalent Ni(7)Ce4As4 tetrahedra, and faces with two equivalent Ni(6)Ce3As4 tetrahedra. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to six equivalent Ce(1) and three equivalent As(1) atoms. In the third Ni site, Ni(3) is bonded in a 5-coordinate geometry to one As(2), two equivalent As(4), and two equivalent As(5) atoms. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to six equivalent Ce(2) and three equivalent As(3) atoms. In the fifth Ni site, Ni(5) is bonded to two equivalent Ce(1), two equivalent Ce(2), one As(3), one As(4), and two equivalent As(1) atoms to form distorted NiCe4As4 tetrahedra that share  a cornercorner with one Ni(1)CeAs4 tetrahedra, corners with two equivalent Ni(6)Ce3As4 tetrahedra, corners with two equivalent Ni(5)Ce4As4 tetrahedra, corners with four equivalent Ni(7)Ce4As4 tetrahedra,  an edgeedge with one Ni(1)CeAs4 tetrahedra, edges with two equivalent Ni(5)Ce4As4 tetrahedra, faces with two equivalent Ni(6)Ce3As4 tetrahedra, and faces with two equivalent Ni(7)Ce4As4 tetrahedra. In the sixth Ni site, Ni(6) is bonded to one Ce(2), two equivalent Ce(1), one As(1), one As(2), and two equivalent As(4) atoms to form distorted NiCe3As4 tetrahedra that share corners with two equivalent Ni(5)Ce4As4 tetrahedra, corners with three equivalent Ni(7)Ce4As4 tetrahedra,  an edgeedge with one Ni(7)Ce4As4 tetrahedra, edges with two equivalent Ni(6)Ce3As4 tetrahedra,  a faceface with one Ni(7)Ce4As4 tetrahedra, faces with two equivalent Ni(5)Ce4As4 tetrahedra, and faces with two equivalent Ni(1)CeAs4 tetrahedra. In the seventh Ni site, Ni(7) is bonded to two equivalent Ce(1), two equivalent Ce(2), one As(1), one As(2), and two equivalent As(3) atoms to form distorted NiCe4As4 tetrahedra that share corners with two equivalent Ni(7)Ce4As4 tetrahedra, corners with three equivalent Ni(6)Ce3As4 tetrahedra, corners with four equivalent Ni(5)Ce4As4 tetrahedra,  an edgeedge with one Ni(6)Ce3As4 tetrahedra, edges with two equivalent Ni(7)Ce4As4 tetrahedra, edges with two equivalent Ni(1)CeAs4 tetrahedra,  a faceface with one Ni(6)Ce3As4 tetrahedra, and faces with two equivalent Ni(5)Ce4As4 tetrahedra. In the eighth Ni site, Ni(8) is bonded in a 4-coordinate geometry to one Ce(1), two equivalent Ce(2), one As(3), one As(4), and two equivalent As(2) atoms. There are five inequivalent As sites. In the first As site, As(3) is bonded in a 9-coordinate geometry to four equivalent Ce(2), one Ni(4), one Ni(5), one Ni(8), and two equivalent Ni(7) atoms. In the second As site, As(4) is bonded in a 9-coordinate geometry to two equivalent Ce(2), one Ni(1), one Ni(5), one Ni(8), two equivalent Ni(3), and two equivalent Ni(6) atoms. In the third As site, As(5) is bonded in a 9-coordinate geometry to three equivalent Ni(1) and six equivalent Ni(3) atoms. In the fourth As site, As(1) is bonded in a 9-coordinate geometry to four equivalent Ce(1), one Ni(2), one Ni(6), one Ni(7), and two equivalent Ni(5) atoms. In the fifth As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Ce(1), one Ni(3), one Ni(6), one Ni(7), two equivalent Ni(1), and two equivalent Ni(8) atoms. is represented by the CIF file [CIF]
data_Ce6Ni20As13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.209
_cell_length_b   13.209
_cell_length_c   3.946
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   596.258
_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
  Ce  Ce0  1  0.719  0.530  0.000  1.0
  Ce  Ce1  1  0.811  0.281  0.000  1.0
  Ce  Ce2  1  0.470  0.189  0.000  1.0
  Ce  Ce3  1  0.532  0.812  0.500  1.0
  Ce  Ce4  1  0.280  0.468  0.500  1.0
  Ce  Ce5  1  0.188  0.720  0.500  1.0
  Ni  Ni6  1  0.891  0.802  0.000  1.0
  Ni  Ni7  1  0.911  0.109  0.000  1.0
  Ni  Ni8  1  0.198  0.089  0.000  1.0
  Ni  Ni9  1  0.667  0.333  0.500  1.0
  Ni  Ni10  1  0.843  0.929  0.500  1.0
  Ni  Ni11  1  0.086  0.157  0.500  1.0
  Ni  Ni12  1  0.071  0.914  0.500  1.0
  Ni  Ni13  1  0.333  0.667  0.000  1.0
  Ni  Ni14  1  0.978  0.564  0.000  1.0
  Ni  Ni15  1  0.586  0.022  0.000  1.0
  Ni  Ni16  1  0.436  0.414  0.000  1.0
  Ni  Ni17  1  0.931  0.684  0.500  1.0
  Ni  Ni18  1  0.753  0.069  0.500  1.0
  Ni  Ni19  1  0.316  0.247  0.500  1.0
  Ni  Ni20  1  0.412  0.978  0.500  1.0
  Ni  Ni21  1  0.566  0.588  0.500  1.0
  Ni  Ni22  1  0.022  0.434  0.500  1.0
  Ni  Ni23  1  0.680  0.755  0.000  1.0
  Ni  Ni24  1  0.075  0.320  0.000  1.0
  Ni  Ni25  1  0.245  0.925  0.000  1.0
  As  As26  1  0.867  0.478  0.500  1.0
  As  As27  1  0.612  0.133  0.500  1.0
  As  As28  1  0.522  0.388  0.500  1.0
  As  As29  1  0.769  0.723  0.500  1.0
  As  As30  1  0.953  0.231  0.500  1.0
  As  As31  1  0.277  0.047  0.500  1.0
  As  As32  1  0.387  0.866  0.000  1.0
  As  As33  1  0.478  0.613  0.000  1.0
  As  As34  1  0.134  0.522  0.000  1.0
  As  As35  1  0.721  0.952  0.000  1.0
  As  As36  1  0.231  0.279  0.000  1.0
  As  As37  1  0.048  0.769  0.000  1.0
  As  As38  1  0.000  0.000  0.000  1.0
[/CIF]
.
The structure described by Ce6Ni20As13 crystallizes in the hexagonal P-6 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 16-coordinate geometry to one Ni(1), one Ni(8), two equivalent Ni(2), two equivalent Ni(5), two equivalent Ni(6), two equivalent Ni(7), two equivalent As(2), and four equivalent As(1) atoms. In the second Ce site, Ce(2) is bonded in a 15-coordinate geometry to one Ni(6), two equivalent Ni(4), two equivalent Ni(5), two equivalent Ni(7), two equivalent Ni(8), two equivalent As(4), and four equivalent As(3) atoms. There are eight inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Ce(1), one As(4), one As(5), and two equivalent As(2) atoms to form distorted NiCeAs4 tetrahedra that share  a cornercorner with one Ni(5)Ce4As4 tetrahedra, corners with four equivalent Ni(1)CeAs4 tetrahedra,  an edgeedge with one Ni(5)Ce4As4 tetrahedra, edges with two equivalent Ni(7)Ce4As4 tetrahedra, and faces with two equivalent Ni(6)Ce3As4 tetrahedra. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to six equivalent Ce(1) and three equivalent As(1) atoms. In the third Ni site, Ni(3) is bonded in a 5-coordinate geometry to one As(2), two equivalent As(4), and two equivalent As(5) atoms. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to six equivalent Ce(2) and three equivalent As(3) atoms. In the fifth Ni site, Ni(5) is bonded to two equivalent Ce(1), two equivalent Ce(2), one As(3), one As(4), and two equivalent As(1) atoms to form distorted NiCe4As4 tetrahedra that share  a cornercorner with one Ni(1)CeAs4 tetrahedra, corners with two equivalent Ni(6)Ce3As4 tetrahedra, corners with two equivalent Ni(5)Ce4As4 tetrahedra, corners with four equivalent Ni(7)Ce4As4 tetrahedra,  an edgeedge with one Ni(1)CeAs4 tetrahedra, edges with two equivalent Ni(5)Ce4As4 tetrahedra, faces with two equivalent Ni(6)Ce3As4 tetrahedra, and faces with two equivalent Ni(7)Ce4As4 tetrahedra. In the sixth Ni site, Ni(6) is bonded to one Ce(2), two equivalent Ce(1), one As(1), one As(2), and two equivalent As(4) atoms to form distorted NiCe3As4 tetrahedra that share corners with two equivalent Ni(5)Ce4As4 tetrahedra, corners with three equivalent Ni(7)Ce4As4 tetrahedra,  an edgeedge with one Ni(7)Ce4As4 tetrahedra, edges with two equivalent Ni(6)Ce3As4 tetrahedra,  a faceface with one Ni(7)Ce4As4 tetrahedra, faces with two equivalent Ni(5)Ce4As4 tetrahedra, and faces with two equivalent Ni(1)CeAs4 tetrahedra. In the seventh Ni site, Ni(7) is bonded to two equivalent Ce(1), two equivalent Ce(2), one As(1), one As(2), and two equivalent As(3) atoms to form distorted NiCe4As4 tetrahedra that share corners with two equivalent Ni(7)Ce4As4 tetrahedra, corners with three equivalent Ni(6)Ce3As4 tetrahedra, corners with four equivalent Ni(5)Ce4As4 tetrahedra,  an edgeedge with one Ni(6)Ce3As4 tetrahedra, edges with two equivalent Ni(7)Ce4As4 tetrahedra, edges with two equivalent Ni(1)CeAs4 tetrahedra,  a faceface with one Ni(6)Ce3As4 tetrahedra, and faces with two equivalent Ni(5)Ce4As4 tetrahedra. In the eighth Ni site, Ni(8) is bonded in a 4-coordinate geometry to one Ce(1), two equivalent Ce(2), one As(3), one As(4), and two equivalent As(2) atoms. There are five inequivalent As sites. In the first As site, As(3) is bonded in a 9-coordinate geometry to four equivalent Ce(2), one Ni(4), one Ni(5), one Ni(8), and two equivalent Ni(7) atoms. In the second As site, As(4) is bonded in a 9-coordinate geometry to two equivalent Ce(2), one Ni(1), one Ni(5), one Ni(8), two equivalent Ni(3), and two equivalent Ni(6) atoms. In the third As site, As(5) is bonded in a 9-coordinate geometry to three equivalent Ni(1) and six equivalent Ni(3) atoms. In the fourth As site, As(1) is bonded in a 9-coordinate geometry to four equivalent Ce(1), one Ni(2), one Ni(6), one Ni(7), and two equivalent Ni(5) atoms. In the fifth As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Ce(1), one Ni(3), one Ni(6), one Ni(7), two equivalent Ni(1), and two equivalent Ni(8) atoms. is represented by the CIF file [CIF]
data_Ce6Ni20As13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.209
_cell_length_b   13.209
_cell_length_c   3.946
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   596.258
_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
  Ce  Ce0  1  0.719  0.530  0.000  1.0
  Ce  Ce1  1  0.811  0.281  0.000  1.0
  Ce  Ce2  1  0.470  0.189  0.000  1.0
  Ce  Ce3  1  0.532  0.812  0.500  1.0
  Ce  Ce4  1  0.280  0.468  0.500  1.0
  Ce  Ce5  1  0.188  0.720  0.500  1.0
  Ni  Ni6  1  0.891  0.802  0.000  1.0
  Ni  Ni7  1  0.911  0.109  0.000  1.0
  Ni  Ni8  1  0.198  0.089  0.000  1.0
  Ni  Ni9  1  0.667  0.333  0.500  1.0
  Ni  Ni10  1  0.843  0.929  0.500  1.0
  Ni  Ni11  1  0.086  0.157  0.500  1.0
  Ni  Ni12  1  0.071  0.914  0.500  1.0
  Ni  Ni13  1  0.333  0.667  0.000  1.0
  Ni  Ni14  1  0.978  0.564  0.000  1.0
  Ni  Ni15  1  0.586  0.022  0.000  1.0
  Ni  Ni16  1  0.436  0.414  0.000  1.0
  Ni  Ni17  1  0.931  0.684  0.500  1.0
  Ni  Ni18  1  0.753  0.069  0.500  1.0
  Ni  Ni19  1  0.316  0.247  0.500  1.0
  Ni  Ni20  1  0.412  0.978  0.500  1.0
  Ni  Ni21  1  0.566  0.588  0.500  1.0
  Ni  Ni22  1  0.022  0.434  0.500  1.0
  Ni  Ni23  1  0.680  0.755  0.000  1.0
  Ni  Ni24  1  0.075  0.320  0.000  1.0
  Ni  Ni25  1  0.245  0.925  0.000  1.0
  As  As26  1  0.867  0.478  0.500  1.0
  As  As27  1  0.612  0.133  0.500  1.0
  As  As28  1  0.522  0.388  0.500  1.0
  As  As29  1  0.769  0.723  0.500  1.0
  As  As30  1  0.953  0.231  0.500  1.0
  As  As31  1  0.277  0.047  0.500  1.0
  As  As32  1  0.387  0.866  0.000  1.0
  As  As33  1  0.478  0.613  0.000  1.0
  As  As34  1  0.134  0.522  0.000  1.0
  As  As35  1  0.721  0.952  0.000  1.0
  As  As36  1  0.231  0.279  0.000  1.0
  As  As37  1  0.048  0.769  0.000  1.0
  As  As38  1  0.000  0.000  0.000  1.0
[/CIF]
.