The crystal structure described by Ni7Tb2 crystallizes in the trigonal R-3m space group. There are six inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. In the second Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3), three equivalent Ni(4), six equivalent Ni(1), and six equivalent Ni(2) atoms. In the third Tb site, Tb(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(1) atoms. In the fourth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. In the fifth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. In the sixth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); and four Ni(2,2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra; corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra; faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra; and faces with eight Ni(2,2)Tb4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); and four equivalent Ni(2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the third Ni site, Ni(1) is bonded to two equivalent Tb(1), three equivalent Tb(2), one Ni(3), one Ni(4), one Ni(5), and four equivalent Ni(1) atoms to form distorted NiTb5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Tb6Ni6 cuboctahedra; corners with six Ni(2,2)Tb4Ni8 cuboctahedra; corners with nine equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with four equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with four equivalent Ni(1)Tb5Ni7 cuboctahedra;  a faceface with one Ni(2)Tb4Ni8 cuboctahedra; faces with three equivalent Ni(5)Tb6Ni6 cuboctahedra; and faces with ten equivalent Ni(1)Tb5Ni7 cuboctahedra. In the fourth Ni site, Ni(2) is bonded to four equivalent Tb(1), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the fifth Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Tb(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the sixth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Tb(1); three equivalent Ni(1); and three Ni(2,2) atoms. In the seventh Ni site, Ni(5) is bonded to six equivalent Tb(2) and six equivalent Ni(1) atoms to form NiTb6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with six equivalent Ni(5)Tb6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Tb5Ni7 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.331
_cell_length_b   12.331
_cell_length_c   12.331
_cell_angle_alpha   23.059
_cell_angle_beta   23.059
_cell_angle_gamma   23.059
_symmetry_Int_Tables_number   1
_cell_volume   252.447
_cell_formula_units_Z   2
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
  Tb  Tb0  1  0.949  0.949  0.949  1.0
  Tb  Tb1  1  0.051  0.051  0.051  1.0
  Tb  Tb2  1  0.852  0.852  0.852  1.0
  Tb  Tb3  1  0.148  0.148  0.148  1.0
  Ni  Ni4  1  0.390  0.890  0.390  1.0
  Ni  Ni5  1  0.390  0.390  0.890  1.0
  Ni  Ni6  1  0.890  0.390  0.390  1.0
  Ni  Ni7  1  0.610  0.110  0.610  1.0
  Ni  Ni8  1  0.610  0.610  0.110  1.0
  Ni  Ni9  1  0.110  0.610  0.610  1.0
  Ni  Ni10  1  0.500  0.500  0.000  1.0
  Ni  Ni11  1  0.000  0.500  0.500  1.0
  Ni  Ni12  1  0.500  0.000  0.500  1.0
  Ni  Ni13  1  0.722  0.722  0.722  1.0
  Ni  Ni14  1  0.278  0.278  0.278  1.0
  Ni  Ni15  1  0.612  0.612  0.612  1.0
  Ni  Ni16  1  0.388  0.388  0.388  1.0
  Ni  Ni17  1  0.500  0.500  0.500  1.0
[/CIF]
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The crystal structure described by Ni7Tb2 crystallizes in the trigonal R-3m space group. There are six inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. In the second Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3), three equivalent Ni(4), six equivalent Ni(1), and six equivalent Ni(2) atoms. In the third Tb site, Tb(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(1) atoms. In the fourth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. In the fifth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2) atoms. In the sixth Tb site, Tb(1) is bonded in a 18-coordinate geometry to three equivalent Ni(3); three equivalent Ni(4); six equivalent Ni(1); and six Ni(2,2,2) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); and four Ni(2,2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra; corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra; faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra; and faces with eight Ni(2,2)Tb4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to four Tb(1,1); two equivalent Ni(3); two equivalent Ni(4); and four equivalent Ni(2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the third Ni site, Ni(1) is bonded to two equivalent Tb(1), three equivalent Tb(2), one Ni(3), one Ni(4), one Ni(5), and four equivalent Ni(1) atoms to form distorted NiTb5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Tb6Ni6 cuboctahedra; corners with six Ni(2,2)Tb4Ni8 cuboctahedra; corners with nine equivalent Ni(1)Tb5Ni7 cuboctahedra; edges with four equivalent Ni(2)Tb4Ni8 cuboctahedra; edges with four equivalent Ni(1)Tb5Ni7 cuboctahedra;  a faceface with one Ni(2)Tb4Ni8 cuboctahedra; faces with three equivalent Ni(5)Tb6Ni6 cuboctahedra; and faces with ten equivalent Ni(1)Tb5Ni7 cuboctahedra. In the fourth Ni site, Ni(2) is bonded to four equivalent Tb(1), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(2) atoms to form NiTb4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Tb4Ni8 cuboctahedra, corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with two equivalent Ni(2)Tb4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Tb5Ni7 cuboctahedra, faces with two equivalent Ni(1)Tb5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Tb4Ni8 cuboctahedra. In the fifth Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Tb(1), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the sixth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Tb(1); three equivalent Ni(1); and three Ni(2,2) atoms. In the seventh Ni site, Ni(5) is bonded to six equivalent Tb(2) and six equivalent Ni(1) atoms to form NiTb6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Tb5Ni7 cuboctahedra, edges with six equivalent Ni(5)Tb6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Tb5Ni7 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.331
_cell_length_b   12.331
_cell_length_c   12.331
_cell_angle_alpha   23.059
_cell_angle_beta   23.059
_cell_angle_gamma   23.059
_symmetry_Int_Tables_number   1
_cell_volume   252.447
_cell_formula_units_Z   2
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
  Tb  Tb0  1  0.949  0.949  0.949  1.0
  Tb  Tb1  1  0.051  0.051  0.051  1.0
  Tb  Tb2  1  0.852  0.852  0.852  1.0
  Tb  Tb3  1  0.148  0.148  0.148  1.0
  Ni  Ni4  1  0.390  0.890  0.390  1.0
  Ni  Ni5  1  0.390  0.390  0.890  1.0
  Ni  Ni6  1  0.890  0.390  0.390  1.0
  Ni  Ni7  1  0.610  0.110  0.610  1.0
  Ni  Ni8  1  0.610  0.610  0.110  1.0
  Ni  Ni9  1  0.110  0.610  0.610  1.0
  Ni  Ni10  1  0.500  0.500  0.000  1.0
  Ni  Ni11  1  0.000  0.500  0.500  1.0
  Ni  Ni12  1  0.500  0.000  0.500  1.0
  Ni  Ni13  1  0.722  0.722  0.722  1.0
  Ni  Ni14  1  0.278  0.278  0.278  1.0
  Ni  Ni15  1  0.612  0.612  0.612  1.0
  Ni  Ni16  1  0.388  0.388  0.388  1.0
  Ni  Ni17  1  0.500  0.500  0.500  1.0
[/CIF]
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