The crystal structure described by Hf27Si6P10 crystallizes in the orthorhombic Immm space group. There are nine inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a distorted rectangular see-saw-like geometry to one Si(1), one P(1), one P(2), and one P(3) atom. In the second Hf site, Hf(2) is bonded in a 4-coordinate geometry to one Si(2), two equivalent Si(1), and one P(1) atom. In the third Hf site, Hf(3) is bonded to two equivalent Si(1), one P(4), and two equivalent P(3) atoms to form distorted HfSi2P3 trigonal bipyramids that share corners with two equivalent Hf(8)P6 pentagonal pyramids, corners with two equivalent Hf(3)Si2P3 trigonal bipyramids,  an edgeedge with one Hf(8)P6 pentagonal pyramid, edges with two equivalent Hf(3)Si2P3 trigonal bipyramids, and  a faceface with one Hf(3)Si2P3 trigonal bipyramid. In the fourth Hf site, Hf(4) is bonded in a 4-coordinate geometry to three equivalent Si(1) and two equivalent P(1) atoms. In the fifth Hf site, Hf(5) is bonded in a 4-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent P(4) atoms. In the sixth Hf site, Hf(6) is bonded in a 6-coordinate geometry to two equivalent Si(2) and four equivalent P(1) atoms. In the seventh Hf site, Hf(7) is bonded to two equivalent P(2) and four equivalent P(1) atoms to form a mixture of distorted edge, face, and corner-sharing HfP6 pentagonal pyramids. In the eighth Hf site, Hf(8) is bonded to two equivalent P(3) and four equivalent P(2) atoms to form distorted HfP6 pentagonal pyramids that share corners with four equivalent Hf(7)P6 pentagonal pyramids, corners with four equivalent Hf(3)Si2P3 trigonal bipyramids, edges with two equivalent Hf(7)P6 pentagonal pyramids, edges with two equivalent Hf(8)P6 pentagonal pyramids, edges with two equivalent Hf(3)Si2P3 trigonal bipyramids, and faces with three equivalent Hf(8)P6 pentagonal pyramids. In the ninth Hf site, Hf(9) is bonded in a distorted square co-planar geometry to two equivalent Si(2) and two equivalent P(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 9-coordinate geometry to one Hf(9), two equivalent Hf(2), two equivalent Hf(6), and four equivalent Hf(5) atoms. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to one Hf(1), one Hf(5), two equivalent Hf(2), two equivalent Hf(3), and three equivalent Hf(4) atoms. There are four inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to one Hf(1), one Hf(2), two equivalent Hf(4), two equivalent Hf(6), and two equivalent Hf(7) atoms. In the second P site, P(2) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(7), and four equivalent Hf(8) atoms. In the third P site, P(3) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(8), and four equivalent Hf(3) atoms. In the fourth P site, P(4) is bonded to one Hf(9), two equivalent Hf(3), and four equivalent Hf(5) atoms to form a mixture of distorted edge and corner-sharing PHf7 pentagonal bipyramids. is represented by the CIF file [CIF]
data_Hf27(Si3P5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.218
_cell_length_b   15.218
_cell_length_c   15.218
_cell_angle_alpha   166.757
_cell_angle_beta   101.847
_cell_angle_gamma   79.705
_symmetry_Int_Tables_number   1
_cell_volume   786.576
_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
  Hf  Hf0  1  0.522  0.392  0.130  1.0
  Hf  Hf1  1  0.478  0.608  0.870  1.0
  Hf  Hf2  1  0.261  0.392  0.870  1.0
  Hf  Hf3  1  0.739  0.608  0.130  1.0
  Hf  Hf4  1  0.315  0.183  0.132  1.0
  Hf  Hf5  1  0.685  0.817  0.868  1.0
  Hf  Hf6  1  0.050  0.183  0.868  1.0
  Hf  Hf7  1  0.950  0.817  0.132  1.0
  Hf  Hf8  1  0.316  0.069  0.247  1.0
  Hf  Hf9  1  0.684  0.931  0.753  1.0
  Hf  Hf10  1  0.822  0.069  0.753  1.0
  Hf  Hf11  1  0.178  0.931  0.247  1.0
  Hf  Hf12  1  0.533  0.216  0.317  1.0
  Hf  Hf13  1  0.467  0.784  0.683  1.0
  Hf  Hf14  1  0.899  0.216  0.683  1.0
  Hf  Hf15  1  0.101  0.784  0.317  1.0
  Hf  Hf16  1  0.827  0.421  0.406  1.0
  Hf  Hf17  1  0.173  0.579  0.594  1.0
  Hf  Hf18  1  0.014  0.421  0.594  1.0
  Hf  Hf19  1  0.986  0.579  0.406  1.0
  Hf  Hf20  1  0.219  0.719  0.500  1.0
  Hf  Hf21  1  0.781  0.281  0.500  1.0
  Hf  Hf22  1  0.352  0.852  0.500  1.0
  Hf  Hf23  1  0.648  0.148  0.500  1.0
  Hf  Hf24  1  0.418  0.000  0.418  1.0
  Hf  Hf25  1  0.582  0.000  0.582  1.0
  Hf  Hf26  1  0.000  0.000  0.000  1.0
  Si  Si27  1  0.610  0.342  0.267  1.0
  Si  Si28  1  0.390  0.658  0.733  1.0
  Si  Si29  1  0.075  0.342  0.733  1.0
  Si  Si30  1  0.925  0.658  0.267  1.0
  Si  Si31  1  0.126  0.126  0.000  1.0
  Si  Si32  1  0.874  0.874  0.000  1.0
  P  P33  1  0.361  0.286  0.075  1.0
  P  P34  1  0.639  0.714  0.925  1.0
  P  P35  1  0.211  0.286  0.925  1.0
  P  P36  1  0.789  0.714  0.075  1.0
  P  P37  1  0.439  0.439  0.000  1.0
  P  P38  1  0.561  0.561  0.000  1.0
  P  P39  1  0.688  0.500  0.188  1.0
  P  P40  1  0.312  0.500  0.812  1.0
  P  P41  1  0.140  0.000  0.140  1.0
  P  P42  1  0.860  0.000  0.860  1.0
[/CIF]
.
The crystal structure described by Hf27Si6P10 crystallizes in the orthorhombic Immm space group. There are nine inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a distorted rectangular see-saw-like geometry to one Si(1), one P(1), one P(2), and one P(3) atom. In the second Hf site, Hf(2) is bonded in a 4-coordinate geometry to one Si(2), two equivalent Si(1), and one P(1) atom. In the third Hf site, Hf(3) is bonded to two equivalent Si(1), one P(4), and two equivalent P(3) atoms to form distorted HfSi2P3 trigonal bipyramids that share corners with two equivalent Hf(8)P6 pentagonal pyramids, corners with two equivalent Hf(3)Si2P3 trigonal bipyramids,  an edgeedge with one Hf(8)P6 pentagonal pyramid, edges with two equivalent Hf(3)Si2P3 trigonal bipyramids, and  a faceface with one Hf(3)Si2P3 trigonal bipyramid. In the fourth Hf site, Hf(4) is bonded in a 4-coordinate geometry to three equivalent Si(1) and two equivalent P(1) atoms. In the fifth Hf site, Hf(5) is bonded in a 4-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent P(4) atoms. In the sixth Hf site, Hf(6) is bonded in a 6-coordinate geometry to two equivalent Si(2) and four equivalent P(1) atoms. In the seventh Hf site, Hf(7) is bonded to two equivalent P(2) and four equivalent P(1) atoms to form a mixture of distorted edge, face, and corner-sharing HfP6 pentagonal pyramids. In the eighth Hf site, Hf(8) is bonded to two equivalent P(3) and four equivalent P(2) atoms to form distorted HfP6 pentagonal pyramids that share corners with four equivalent Hf(7)P6 pentagonal pyramids, corners with four equivalent Hf(3)Si2P3 trigonal bipyramids, edges with two equivalent Hf(7)P6 pentagonal pyramids, edges with two equivalent Hf(8)P6 pentagonal pyramids, edges with two equivalent Hf(3)Si2P3 trigonal bipyramids, and faces with three equivalent Hf(8)P6 pentagonal pyramids. In the ninth Hf site, Hf(9) is bonded in a distorted square co-planar geometry to two equivalent Si(2) and two equivalent P(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 9-coordinate geometry to one Hf(9), two equivalent Hf(2), two equivalent Hf(6), and four equivalent Hf(5) atoms. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to one Hf(1), one Hf(5), two equivalent Hf(2), two equivalent Hf(3), and three equivalent Hf(4) atoms. There are four inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to one Hf(1), one Hf(2), two equivalent Hf(4), two equivalent Hf(6), and two equivalent Hf(7) atoms. In the second P site, P(2) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(7), and four equivalent Hf(8) atoms. In the third P site, P(3) is bonded in a 8-coordinate geometry to two equivalent Hf(1), two equivalent Hf(8), and four equivalent Hf(3) atoms. In the fourth P site, P(4) is bonded to one Hf(9), two equivalent Hf(3), and four equivalent Hf(5) atoms to form a mixture of distorted edge and corner-sharing PHf7 pentagonal bipyramids. is represented by the CIF file [CIF]
data_Hf27(Si3P5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.218
_cell_length_b   15.218
_cell_length_c   15.218
_cell_angle_alpha   166.757
_cell_angle_beta   101.847
_cell_angle_gamma   79.705
_symmetry_Int_Tables_number   1
_cell_volume   786.576
_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
  Hf  Hf0  1  0.522  0.392  0.130  1.0
  Hf  Hf1  1  0.478  0.608  0.870  1.0
  Hf  Hf2  1  0.261  0.392  0.870  1.0
  Hf  Hf3  1  0.739  0.608  0.130  1.0
  Hf  Hf4  1  0.315  0.183  0.132  1.0
  Hf  Hf5  1  0.685  0.817  0.868  1.0
  Hf  Hf6  1  0.050  0.183  0.868  1.0
  Hf  Hf7  1  0.950  0.817  0.132  1.0
  Hf  Hf8  1  0.316  0.069  0.247  1.0
  Hf  Hf9  1  0.684  0.931  0.753  1.0
  Hf  Hf10  1  0.822  0.069  0.753  1.0
  Hf  Hf11  1  0.178  0.931  0.247  1.0
  Hf  Hf12  1  0.533  0.216  0.317  1.0
  Hf  Hf13  1  0.467  0.784  0.683  1.0
  Hf  Hf14  1  0.899  0.216  0.683  1.0
  Hf  Hf15  1  0.101  0.784  0.317  1.0
  Hf  Hf16  1  0.827  0.421  0.406  1.0
  Hf  Hf17  1  0.173  0.579  0.594  1.0
  Hf  Hf18  1  0.014  0.421  0.594  1.0
  Hf  Hf19  1  0.986  0.579  0.406  1.0
  Hf  Hf20  1  0.219  0.719  0.500  1.0
  Hf  Hf21  1  0.781  0.281  0.500  1.0
  Hf  Hf22  1  0.352  0.852  0.500  1.0
  Hf  Hf23  1  0.648  0.148  0.500  1.0
  Hf  Hf24  1  0.418  0.000  0.418  1.0
  Hf  Hf25  1  0.582  0.000  0.582  1.0
  Hf  Hf26  1  0.000  0.000  0.000  1.0
  Si  Si27  1  0.610  0.342  0.267  1.0
  Si  Si28  1  0.390  0.658  0.733  1.0
  Si  Si29  1  0.075  0.342  0.733  1.0
  Si  Si30  1  0.925  0.658  0.267  1.0
  Si  Si31  1  0.126  0.126  0.000  1.0
  Si  Si32  1  0.874  0.874  0.000  1.0
  P  P33  1  0.361  0.286  0.075  1.0
  P  P34  1  0.639  0.714  0.925  1.0
  P  P35  1  0.211  0.286  0.925  1.0
  P  P36  1  0.789  0.714  0.075  1.0
  P  P37  1  0.439  0.439  0.000  1.0
  P  P38  1  0.561  0.561  0.000  1.0
  P  P39  1  0.688  0.500  0.188  1.0
  P  P40  1  0.312  0.500  0.812  1.0
  P  P41  1  0.140  0.000  0.140  1.0
  P  P42  1  0.860  0.000  0.860  1.0
[/CIF]
.