The structure described by K4Sn9 is Magnesium tetraboride-like structured and crystallizes in the monoclinic P2_1/c space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one Sn(3), one Sn(4), one Sn(5), one Sn(6), one Sn(7), and two equivalent Sn(8) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one Sn(3), one Sn(4), one Sn(5), two equivalent Sn(6), and two equivalent Sn(8) atoms. In the third K site, K(3) is bonded in a 8-coordinate geometry to one Sn(4), one Sn(5), one Sn(7), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(9) atoms. In the fourth K site, K(4) is bonded in a 8-coordinate geometry to one Sn(2), one Sn(3), one Sn(4), one Sn(5), one Sn(6), one Sn(9), and two equivalent Sn(1) atoms. There are nine inequivalent Sn sites. In the first Sn site, Sn(9) is bonded in a 8-coordinate geometry to one K(4), two equivalent K(3), one Sn(1), one Sn(2), one Sn(3), one Sn(5), and one Sn(7) atom. In the second Sn site, Sn(1) is bonded in a 8-coordinate geometry to two equivalent K(3), two equivalent K(4), one Sn(2), one Sn(4), one Sn(7), and one Sn(9) atom. In the third Sn site, Sn(2) is bonded in a 8-coordinate geometry to one K(4), two equivalent K(3), one Sn(1), one Sn(4), one Sn(5), one Sn(8), and one Sn(9) atom. In the fourth Sn site, Sn(3) is bonded in a 8-coordinate geometry to one K(1), one K(2), one K(4), one Sn(5), one Sn(6), one Sn(7), one Sn(8), and one Sn(9) atom. In the fifth Sn site, Sn(4) is bonded in a 8-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one Sn(1), one Sn(2), one Sn(6), and one Sn(8) atom. In the sixth Sn site, Sn(5) is bonded in a 8-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one Sn(2), one Sn(3), one Sn(8), and one Sn(9) atom. In the seventh Sn site, Sn(6) is bonded in a 8-coordinate geometry to one K(1), one K(4), two equivalent K(2), one Sn(3), one Sn(4), one Sn(7), and one Sn(8) atom. In the eighth Sn site, Sn(7) is bonded in a 6-coordinate geometry to one K(1), one K(3), one Sn(1), one Sn(3), one Sn(6), and one Sn(9) atom. In the ninth Sn site, Sn(8) is bonded in a 9-coordinate geometry to two equivalent K(1), two equivalent K(2), one Sn(2), one Sn(3), one Sn(4), one Sn(5), and one Sn(6) atom. is represented by the CIF card [CIF]
data_K4Sn9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.469
_cell_length_b   14.466
_cell_length_c   16.724
_cell_angle_alpha   84.888
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   2040.830
_cell_formula_units_Z   4
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
  K  K0  1  0.970  0.612  0.357  1.0
  K  K1  1  0.561  0.509  0.616  1.0
  K  K2  1  0.530  0.612  0.857  1.0
  K  K3  1  0.439  0.491  0.384  1.0
  K  K4  1  0.429  0.075  0.238  1.0
  K  K5  1  0.571  0.925  0.762  1.0
  K  K6  1  0.470  0.388  0.143  1.0
  K  K7  1  0.565  0.837  0.447  1.0
  K  K8  1  0.935  0.837  0.947  1.0
  K  K9  1  0.071  0.075  0.738  1.0
  K  K10  1  0.435  0.163  0.553  1.0
  K  K11  1  0.061  0.491  0.884  1.0
  K  K12  1  0.030  0.388  0.643  1.0
  K  K13  1  0.065  0.163  0.053  1.0
  K  K14  1  0.929  0.925  0.262  1.0
  K  K15  1  0.939  0.509  0.116  1.0
  Sn  Sn16  1  0.756  0.074  0.408  1.0
  Sn  Sn17  1  0.825  0.182  0.247  1.0
  Sn  Sn18  1  0.110  0.328  0.431  1.0
  Sn  Sn19  1  0.926  0.253  0.857  1.0
  Sn  Sn20  1  0.256  0.926  0.092  1.0
  Sn  Sn21  1  0.390  0.328  0.931  1.0
  Sn  Sn22  1  0.621  0.708  0.241  1.0
  Sn  Sn23  1  0.234  0.645  0.526  1.0
  Sn  Sn24  1  0.574  0.253  0.357  1.0
  Sn  Sn25  1  0.379  0.292  0.759  1.0
  Sn  Sn26  1  0.610  0.672  0.069  1.0
  Sn  Sn27  1  0.766  0.355  0.474  1.0
  Sn  Sn28  1  0.931  0.174  0.531  1.0
  Sn  Sn29  1  0.744  0.074  0.908  1.0
  Sn  Sn30  1  0.320  0.610  0.202  1.0
  Sn  Sn31  1  0.069  0.826  0.469  1.0
  Sn  Sn32  1  0.426  0.747  0.643  1.0
  Sn  Sn33  1  0.244  0.926  0.592  1.0
  Sn  Sn34  1  0.175  0.818  0.753  1.0
  Sn  Sn35  1  0.879  0.708  0.741  1.0
  Sn  Sn36  1  0.102  0.123  0.380  1.0
  Sn  Sn37  1  0.569  0.174  0.031  1.0
  Sn  Sn38  1  0.325  0.818  0.253  1.0
  Sn  Sn39  1  0.680  0.390  0.798  1.0
  Sn  Sn40  1  0.266  0.645  0.026  1.0
  Sn  Sn41  1  0.398  0.123  0.880  1.0
  Sn  Sn42  1  0.431  0.826  0.969  1.0
  Sn  Sn43  1  0.180  0.610  0.702  1.0
  Sn  Sn44  1  0.734  0.355  0.974  1.0
  Sn  Sn45  1  0.121  0.292  0.259  1.0
  Sn  Sn46  1  0.890  0.672  0.569  1.0
  Sn  Sn47  1  0.675  0.182  0.747  1.0
  Sn  Sn48  1  0.820  0.390  0.298  1.0
  Sn  Sn49  1  0.602  0.877  0.120  1.0
  Sn  Sn50  1  0.898  0.877  0.620  1.0
  Sn  Sn51  1  0.074  0.747  0.143  1.0
[/CIF]
.
The structure described by K4Sn9 is Magnesium tetraboride-like structured and crystallizes in the monoclinic P2_1/c space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one Sn(3), one Sn(4), one Sn(5), one Sn(6), one Sn(7), and two equivalent Sn(8) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one Sn(3), one Sn(4), one Sn(5), two equivalent Sn(6), and two equivalent Sn(8) atoms. In the third K site, K(3) is bonded in a 8-coordinate geometry to one Sn(4), one Sn(5), one Sn(7), two equivalent Sn(1), two equivalent Sn(2), and two equivalent Sn(9) atoms. In the fourth K site, K(4) is bonded in a 8-coordinate geometry to one Sn(2), one Sn(3), one Sn(4), one Sn(5), one Sn(6), one Sn(9), and two equivalent Sn(1) atoms. There are nine inequivalent Sn sites. In the first Sn site, Sn(9) is bonded in a 8-coordinate geometry to one K(4), two equivalent K(3), one Sn(1), one Sn(2), one Sn(3), one Sn(5), and one Sn(7) atom. In the second Sn site, Sn(1) is bonded in a 8-coordinate geometry to two equivalent K(3), two equivalent K(4), one Sn(2), one Sn(4), one Sn(7), and one Sn(9) atom. In the third Sn site, Sn(2) is bonded in a 8-coordinate geometry to one K(4), two equivalent K(3), one Sn(1), one Sn(4), one Sn(5), one Sn(8), and one Sn(9) atom. In the fourth Sn site, Sn(3) is bonded in a 8-coordinate geometry to one K(1), one K(2), one K(4), one Sn(5), one Sn(6), one Sn(7), one Sn(8), and one Sn(9) atom. In the fifth Sn site, Sn(4) is bonded in a 8-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one Sn(1), one Sn(2), one Sn(6), and one Sn(8) atom. In the sixth Sn site, Sn(5) is bonded in a 8-coordinate geometry to one K(1), one K(2), one K(3), one K(4), one Sn(2), one Sn(3), one Sn(8), and one Sn(9) atom. In the seventh Sn site, Sn(6) is bonded in a 8-coordinate geometry to one K(1), one K(4), two equivalent K(2), one Sn(3), one Sn(4), one Sn(7), and one Sn(8) atom. In the eighth Sn site, Sn(7) is bonded in a 6-coordinate geometry to one K(1), one K(3), one Sn(1), one Sn(3), one Sn(6), and one Sn(9) atom. In the ninth Sn site, Sn(8) is bonded in a 9-coordinate geometry to two equivalent K(1), two equivalent K(2), one Sn(2), one Sn(3), one Sn(4), one Sn(5), and one Sn(6) atom. is represented by the CIF card [CIF]
data_K4Sn9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.469
_cell_length_b   14.466
_cell_length_c   16.724
_cell_angle_alpha   84.888
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   2040.830
_cell_formula_units_Z   4
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
  K  K0  1  0.970  0.612  0.357  1.0
  K  K1  1  0.561  0.509  0.616  1.0
  K  K2  1  0.530  0.612  0.857  1.0
  K  K3  1  0.439  0.491  0.384  1.0
  K  K4  1  0.429  0.075  0.238  1.0
  K  K5  1  0.571  0.925  0.762  1.0
  K  K6  1  0.470  0.388  0.143  1.0
  K  K7  1  0.565  0.837  0.447  1.0
  K  K8  1  0.935  0.837  0.947  1.0
  K  K9  1  0.071  0.075  0.738  1.0
  K  K10  1  0.435  0.163  0.553  1.0
  K  K11  1  0.061  0.491  0.884  1.0
  K  K12  1  0.030  0.388  0.643  1.0
  K  K13  1  0.065  0.163  0.053  1.0
  K  K14  1  0.929  0.925  0.262  1.0
  K  K15  1  0.939  0.509  0.116  1.0
  Sn  Sn16  1  0.756  0.074  0.408  1.0
  Sn  Sn17  1  0.825  0.182  0.247  1.0
  Sn  Sn18  1  0.110  0.328  0.431  1.0
  Sn  Sn19  1  0.926  0.253  0.857  1.0
  Sn  Sn20  1  0.256  0.926  0.092  1.0
  Sn  Sn21  1  0.390  0.328  0.931  1.0
  Sn  Sn22  1  0.621  0.708  0.241  1.0
  Sn  Sn23  1  0.234  0.645  0.526  1.0
  Sn  Sn24  1  0.574  0.253  0.357  1.0
  Sn  Sn25  1  0.379  0.292  0.759  1.0
  Sn  Sn26  1  0.610  0.672  0.069  1.0
  Sn  Sn27  1  0.766  0.355  0.474  1.0
  Sn  Sn28  1  0.931  0.174  0.531  1.0
  Sn  Sn29  1  0.744  0.074  0.908  1.0
  Sn  Sn30  1  0.320  0.610  0.202  1.0
  Sn  Sn31  1  0.069  0.826  0.469  1.0
  Sn  Sn32  1  0.426  0.747  0.643  1.0
  Sn  Sn33  1  0.244  0.926  0.592  1.0
  Sn  Sn34  1  0.175  0.818  0.753  1.0
  Sn  Sn35  1  0.879  0.708  0.741  1.0
  Sn  Sn36  1  0.102  0.123  0.380  1.0
  Sn  Sn37  1  0.569  0.174  0.031  1.0
  Sn  Sn38  1  0.325  0.818  0.253  1.0
  Sn  Sn39  1  0.680  0.390  0.798  1.0
  Sn  Sn40  1  0.266  0.645  0.026  1.0
  Sn  Sn41  1  0.398  0.123  0.880  1.0
  Sn  Sn42  1  0.431  0.826  0.969  1.0
  Sn  Sn43  1  0.180  0.610  0.702  1.0
  Sn  Sn44  1  0.734  0.355  0.974  1.0
  Sn  Sn45  1  0.121  0.292  0.259  1.0
  Sn  Sn46  1  0.890  0.672  0.569  1.0
  Sn  Sn47  1  0.675  0.182  0.747  1.0
  Sn  Sn48  1  0.820  0.390  0.298  1.0
  Sn  Sn49  1  0.602  0.877  0.120  1.0
  Sn  Sn50  1  0.898  0.877  0.620  1.0
  Sn  Sn51  1  0.074  0.747  0.143  1.0
[/CIF]
.