The material structure described by Y2Ni7 crystallizes in the trigonal R-3m space group. There are five inequivalent Y sites. In the first Y site, Y(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent Ni(4) atoms. In the second Y site, Y(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(3) atoms. In the third Y site, Y(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 fourth Y site, Y(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 Y site, Y(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 eight inequivalent Ni sites. In the first Ni site, Ni(4) is bonded to four Y(1,1); two equivalent Ni(1); two equivalent Ni(2); and four equivalent Ni(4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra, edges with two equivalent Ni(4)Y4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra, faces with two equivalent Ni(3)Y5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Y4Ni8 cuboctahedra. In the second Ni site, Ni(1) is bonded in a 9-coordinate geometry to three equivalent Y(1); three equivalent Ni(3); and three Ni(4,4) atoms. In the third Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Y(1); three equivalent Ni(3); and three Ni(4,4) atoms. In the fourth Ni site, Ni(3) is bonded to two equivalent Y(1), three equivalent Y(2), one Ni(1), one Ni(2), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiY5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Y6Ni6 cuboctahedra, corners with six equivalent Ni(4)Y4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Y5Ni7 cuboctahedra, edges with four equivalent Ni(4)Y4Ni8 cuboctahedra, edges with four equivalent Ni(3)Y5Ni7 cuboctahedra,  a faceface with one Ni(4)Y4Ni8 cuboctahedra, faces with three equivalent Ni(5)Y6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Y5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded to four equivalent Y(1), two equivalent Ni(1), two equivalent Ni(2), and four equivalent Ni(4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra, edges with two equivalent Ni(4)Y4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra, faces with two equivalent Ni(3)Y5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Y4Ni8 cuboctahedra. In the sixth Ni site, Ni(5) is bonded to six equivalent Y(2) and six equivalent Ni(3) atoms to form NiY6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra, edges with six equivalent Ni(5)Y6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Y5Ni7 cuboctahedra. In the seventh Ni site, Ni(4) is bonded to four Y(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra; edges with two equivalent Ni(4)Y4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra; faces with two equivalent Ni(3)Y5Ni7 cuboctahedra; and faces with eight Ni(4,4)Y4Ni8 cuboctahedra. In the eighth Ni site, Ni(4) is bonded to four Y(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra; edges with two equivalent Ni(4)Y4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra; faces with two equivalent Ni(3)Y5Ni7 cuboctahedra; and faces with eight Ni(4,4)Y4Ni8 cuboctahedra. is represented by the CIF card [CIF]
data_Y2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.369
_cell_length_b   12.369
_cell_length_c   12.369
_cell_angle_alpha   23.029
_cell_angle_beta   23.029
_cell_angle_gamma   23.029
_symmetry_Int_Tables_number   1
_cell_volume   254.144
_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
  Y  Y0  1  0.950  0.950  0.950  1.0
  Y  Y1  1  0.147  0.147  0.147  1.0
  Y  Y2  1  0.050  0.050  0.050  1.0
  Y  Y3  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  0.390  0.891  0.390  1.0
  Ni  Ni7  1  0.612  0.612  0.612  1.0
  Ni  Ni8  1  0.000  0.500  0.500  1.0
  Ni  Ni9  1  0.610  0.610  0.109  1.0
  Ni  Ni10  1  0.500  0.500  0.500  1.0
  Ni  Ni11  1  0.390  0.390  0.891  1.0
  Ni  Ni12  1  0.278  0.278  0.278  1.0
  Ni  Ni13  1  0.610  0.109  0.610  1.0
  Ni  Ni14  1  0.891  0.390  0.390  1.0
  Ni  Ni15  1  0.500  0.000  0.500  1.0
  Ni  Ni16  1  0.500  0.500  0.000  1.0
  Ni  Ni17  1  0.109  0.610  0.610  1.0
[/CIF]
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The material structure described by Y2Ni7 crystallizes in the trigonal R-3m space group. There are five inequivalent Y sites. In the first Y site, Y(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent Ni(4) atoms. In the second Y site, Y(2) is bonded in a 12-coordinate geometry to three equivalent Ni(5) and nine equivalent Ni(3) atoms. In the third Y site, Y(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 fourth Y site, Y(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 Y site, Y(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 eight inequivalent Ni sites. In the first Ni site, Ni(4) is bonded to four Y(1,1); two equivalent Ni(1); two equivalent Ni(2); and four equivalent Ni(4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra, edges with two equivalent Ni(4)Y4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra, faces with two equivalent Ni(3)Y5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Y4Ni8 cuboctahedra. In the second Ni site, Ni(1) is bonded in a 9-coordinate geometry to three equivalent Y(1); three equivalent Ni(3); and three Ni(4,4) atoms. In the third Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Y(1); three equivalent Ni(3); and three Ni(4,4) atoms. In the fourth Ni site, Ni(3) is bonded to two equivalent Y(1), three equivalent Y(2), one Ni(1), one Ni(2), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiY5Ni7 cuboctahedra that share corners with two equivalent Ni(5)Y6Ni6 cuboctahedra, corners with six equivalent Ni(4)Y4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Y5Ni7 cuboctahedra, edges with four equivalent Ni(4)Y4Ni8 cuboctahedra, edges with four equivalent Ni(3)Y5Ni7 cuboctahedra,  a faceface with one Ni(4)Y4Ni8 cuboctahedra, faces with three equivalent Ni(5)Y6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Y5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded to four equivalent Y(1), two equivalent Ni(1), two equivalent Ni(2), and four equivalent Ni(4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra, edges with two equivalent Ni(4)Y4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra, faces with two equivalent Ni(3)Y5Ni7 cuboctahedra, and faces with eight equivalent Ni(4)Y4Ni8 cuboctahedra. In the sixth Ni site, Ni(5) is bonded to six equivalent Y(2) and six equivalent Ni(3) atoms to form NiY6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra, edges with six equivalent Ni(5)Y6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Y5Ni7 cuboctahedra. In the seventh Ni site, Ni(4) is bonded to four Y(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra; edges with two equivalent Ni(4)Y4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra; faces with two equivalent Ni(3)Y5Ni7 cuboctahedra; and faces with eight Ni(4,4)Y4Ni8 cuboctahedra. In the eighth Ni site, Ni(4) is bonded to four Y(1,1); two equivalent Ni(1); two equivalent Ni(2); and four Ni(4,4) atoms to form NiY4Ni8 cuboctahedra that share corners with four equivalent Ni(4)Y4Ni8 cuboctahedra; corners with twelve equivalent Ni(3)Y5Ni7 cuboctahedra; edges with two equivalent Ni(4)Y4Ni8 cuboctahedra; edges with eight equivalent Ni(3)Y5Ni7 cuboctahedra; faces with two equivalent Ni(3)Y5Ni7 cuboctahedra; and faces with eight Ni(4,4)Y4Ni8 cuboctahedra. is represented by the CIF card [CIF]
data_Y2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.369
_cell_length_b   12.369
_cell_length_c   12.369
_cell_angle_alpha   23.029
_cell_angle_beta   23.029
_cell_angle_gamma   23.029
_symmetry_Int_Tables_number   1
_cell_volume   254.144
_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
  Y  Y0  1  0.950  0.950  0.950  1.0
  Y  Y1  1  0.147  0.147  0.147  1.0
  Y  Y2  1  0.050  0.050  0.050  1.0
  Y  Y3  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  0.390  0.891  0.390  1.0
  Ni  Ni7  1  0.612  0.612  0.612  1.0
  Ni  Ni8  1  0.000  0.500  0.500  1.0
  Ni  Ni9  1  0.610  0.610  0.109  1.0
  Ni  Ni10  1  0.500  0.500  0.500  1.0
  Ni  Ni11  1  0.390  0.390  0.891  1.0
  Ni  Ni12  1  0.278  0.278  0.278  1.0
  Ni  Ni13  1  0.610  0.109  0.610  1.0
  Ni  Ni14  1  0.891  0.390  0.390  1.0
  Ni  Ni15  1  0.500  0.000  0.500  1.0
  Ni  Ni16  1  0.500  0.500  0.000  1.0
  Ni  Ni17  1  0.109  0.610  0.610  1.0
[/CIF]
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