The structure described by Gd2Ni7 crystallizes in the trigonal R-3m space group. There are seven inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. In the second Gd site, Gd(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(3) atoms. In the third Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4,4) atoms. In the fourth Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. In the fifth Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. In the sixth Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4,4) atoms. In the seventh Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 9-coordinate geometry to three equivalent Gd(1); three equivalent Ni(3); and three Ni(4,4,4) atoms. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Gd(1); three equivalent Ni(3); and three Ni(4,4,4) atoms. In the third Ni site, Ni(3) is bonded to two equivalent Gd(1), three equivalent Gd(2), one Ni(1), one Ni(2), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiGd5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Gd6Ni6 cuboctahedra; corners with six Ni(4,4,4)Gd4Ni8 cuboctahedra; corners with nine equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with four Ni(4,4)Gd4Ni8 cuboctahedra; edges with four equivalent Ni(3)Gd5Ni7 cuboctahedra;  a faceface with one Ni(4)Gd4Ni8 cuboctahedra; faces with three equivalent Ni(5)Gd6Ni6 cuboctahedra; and faces with ten equivalent Ni(3)Gd5Ni7 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to four Gd(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiGd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Gd4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Gd4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Gd5Ni7 cuboctahedra; faces with two equivalent Ni(3)Gd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Gd4Ni8 cuboctahedra. In the fifth Ni site, Ni(5) is bonded to six equivalent Gd(2) and six equivalent Ni(3) atoms to form NiGd6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra, edges with six equivalent Ni(5)Gd6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Gd5Ni7 cuboctahedra. In the sixth Ni site, Ni(4) is bonded to four Gd(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiGd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Gd4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Gd4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Gd5Ni7 cuboctahedra; faces with two equivalent Ni(3)Gd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Gd4Ni8 cuboctahedra. In the seventh Ni site, Ni(4) is bonded to four Gd(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiGd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Gd4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Gd4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Gd5Ni7 cuboctahedra; faces with two equivalent Ni(3)Gd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Gd4Ni8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Gd2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.347
_cell_length_b   12.347
_cell_length_c   12.347
_cell_angle_alpha   23.112
_cell_angle_beta   23.112
_cell_angle_gamma   23.112
_symmetry_Int_Tables_number   1
_cell_volume   254.592
_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
  Gd  Gd0  1  0.949  0.949  0.949  1.0
  Gd  Gd1  1  0.147  0.147  0.147  1.0
  Gd  Gd2  1  0.051  0.051  0.051  1.0
  Gd  Gd3  1  0.853  0.853  0.853  1.0
  Ni  Ni4  1  0.722  0.722  0.722  1.0
  Ni  Ni5  1  0.388  0.388  0.388  1.0
  Ni  Ni6  1  0.110  0.610  0.610  1.0
  Ni  Ni7  1  0.610  0.110  0.610  1.0
  Ni  Ni8  1  0.390  0.390  0.890  1.0
  Ni  Ni9  1  0.612  0.612  0.612  1.0
  Ni  Ni10  1  0.500  0.000  0.500  1.0
  Ni  Ni11  1  0.890  0.390  0.390  1.0
  Ni  Ni12  1  0.500  0.500  0.500  1.0
  Ni  Ni13  1  0.390  0.890  0.390  1.0
  Ni  Ni14  1  0.278  0.278  0.278  1.0
  Ni  Ni15  1  0.610  0.610  0.110  1.0
  Ni  Ni16  1  0.000  0.500  0.500  1.0
  Ni  Ni17  1  0.500  0.500  0.000  1.0
[/CIF]
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The structure described by Gd2Ni7 crystallizes in the trigonal R-3m space group. There are seven inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. In the second Gd site, Gd(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(3) atoms. In the third Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4,4) atoms. In the fourth Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. In the fifth Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. In the sixth Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4,4) atoms. In the seventh Gd site, Gd(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1); three equivalent Ni(2); six equivalent Ni(3); and six Ni(4,4) atoms. There are seven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 9-coordinate geometry to three equivalent Gd(1); three equivalent Ni(3); and three Ni(4,4,4) atoms. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Gd(1); three equivalent Ni(3); and three Ni(4,4,4) atoms. In the third Ni site, Ni(3) is bonded to two equivalent Gd(1), three equivalent Gd(2), one Ni(1), one Ni(2), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiGd5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Gd6Ni6 cuboctahedra; corners with six Ni(4,4,4)Gd4Ni8 cuboctahedra; corners with nine equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with four Ni(4,4)Gd4Ni8 cuboctahedra; edges with four equivalent Ni(3)Gd5Ni7 cuboctahedra;  a faceface with one Ni(4)Gd4Ni8 cuboctahedra; faces with three equivalent Ni(5)Gd6Ni6 cuboctahedra; and faces with ten equivalent Ni(3)Gd5Ni7 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to four Gd(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiGd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Gd4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Gd4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Gd5Ni7 cuboctahedra; faces with two equivalent Ni(3)Gd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Gd4Ni8 cuboctahedra. In the fifth Ni site, Ni(5) is bonded to six equivalent Gd(2) and six equivalent Ni(3) atoms to form NiGd6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra, edges with six equivalent Ni(5)Gd6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Gd5Ni7 cuboctahedra. In the sixth Ni site, Ni(4) is bonded to four Gd(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiGd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Gd4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Gd4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Gd5Ni7 cuboctahedra; faces with two equivalent Ni(3)Gd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Gd4Ni8 cuboctahedra. In the seventh Ni site, Ni(4) is bonded to four Gd(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiGd4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Gd4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Gd5Ni7 cuboctahedra; edges with two equivalent Ni(4)Gd4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Gd5Ni7 cuboctahedra; faces with two equivalent Ni(3)Gd5Ni7 cuboctahedra; and faces with eight Ni(4,4)Gd4Ni8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Gd2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.347
_cell_length_b   12.347
_cell_length_c   12.347
_cell_angle_alpha   23.112
_cell_angle_beta   23.112
_cell_angle_gamma   23.112
_symmetry_Int_Tables_number   1
_cell_volume   254.592
_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
  Gd  Gd0  1  0.949  0.949  0.949  1.0
  Gd  Gd1  1  0.147  0.147  0.147  1.0
  Gd  Gd2  1  0.051  0.051  0.051  1.0
  Gd  Gd3  1  0.853  0.853  0.853  1.0
  Ni  Ni4  1  0.722  0.722  0.722  1.0
  Ni  Ni5  1  0.388  0.388  0.388  1.0
  Ni  Ni6  1  0.110  0.610  0.610  1.0
  Ni  Ni7  1  0.610  0.110  0.610  1.0
  Ni  Ni8  1  0.390  0.390  0.890  1.0
  Ni  Ni9  1  0.612  0.612  0.612  1.0
  Ni  Ni10  1  0.500  0.000  0.500  1.0
  Ni  Ni11  1  0.890  0.390  0.390  1.0
  Ni  Ni12  1  0.500  0.500  0.500  1.0
  Ni  Ni13  1  0.390  0.890  0.390  1.0
  Ni  Ni14  1  0.278  0.278  0.278  1.0
  Ni  Ni15  1  0.610  0.610  0.110  1.0
  Ni  Ni16  1  0.000  0.500  0.500  1.0
  Ni  Ni17  1  0.500  0.500  0.000  1.0
[/CIF]
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