The compound described by BeF2 crystallizes in the monoclinic P2_1 space group. There are eight inequivalent Be sites. In the first Be site, Be(1) is bonded to one F(1), one F(10), one F(12), and one F(2) atom to form corner-sharing BeF4 tetrahedra. In the second Be site, Be(2) is bonded to one F(1), one F(3), one F(5), and one F(8) atom to form corner-sharing BeF4 tetrahedra. In the third Be site, Be(3) is bonded in a trigonal planar geometry to one F(2), one F(3), and one F(4) atom. In the fourth Be site, Be(4) is bonded to one F(4), one F(6), one F(7), and one F(8) atom to form corner-sharing BeF4 tetrahedra. In the fifth Be site, Be(5) is bonded to one F(10), one F(11), one F(13), and one F(9) atom to form corner-sharing BeF4 tetrahedra. In the sixth Be site, Be(6) is bonded in a trigonal planar geometry to one F(13), one F(14), and one F(15) atom. In the seventh Be site, Be(7) is bonded to one F(12), one F(14), one F(16), and one F(9) atom to form corner-sharing BeF4 tetrahedra. In the eighth Be site, Be(8) is bonded to one F(15), one F(16), one F(5), and one F(7) atom to form corner-sharing BeF4 tetrahedra. There are sixteen inequivalent F sites. In the first F site, F(1) is bonded in a bent 120 degrees geometry to one Be(1) and one Be(2) atom. In the second F site, F(2) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(3) atom. In the third F site, F(3) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(3) atom. In the fourth F site, F(4) is bonded in a bent 150 degrees geometry to one Be(3) and one Be(4) atom. In the fifth F site, F(5) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(8) atom. In the sixth F site, F(6) is bonded in a single-bond geometry to one Be(4) atom. In the seventh F site, F(7) is bonded in a bent 150 degrees geometry to one Be(4) and one Be(8) atom. In the eighth F site, F(8) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(4) atom. In the ninth F site, F(9) is bonded in a bent 150 degrees geometry to one Be(5) and one Be(7) atom. In the tenth F site, F(10) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(5) atom. In the eleventh F site, F(11) is bonded in a single-bond geometry to one Be(5) atom. In the twelfth F site, F(12) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(7) atom. In the thirteenth F site, F(13) is bonded in a bent 150 degrees geometry to one Be(5) and one Be(6) atom. In the fourteenth F site, F(14) is bonded in a bent 150 degrees geometry to one Be(6) and one Be(7) atom. In the fifteenth F site, F(15) is bonded in a bent 150 degrees geometry to one Be(6) and one Be(8) atom. In the sixteenth F site, F(16) is bonded in a bent 120 degrees geometry to one Be(7) and one Be(8) atom. is represented by the CIF card [CIF]
data_BeF2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.622
_cell_length_b   6.930
_cell_length_c   7.167
_cell_angle_alpha   62.038
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   553.678
_cell_formula_units_Z   16
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
  Be  Be0  1  0.893  0.451  0.643  1.0
  Be  Be1  1  0.835  0.008  0.905  1.0
  Be  Be2  1  0.893  0.556  0.185  1.0
  Be  Be3  1  0.898  0.087  0.266  1.0
  Be  Be4  1  0.603  0.414  0.234  1.0
  Be  Be5  1  0.606  0.945  0.319  1.0
  Be  Be6  1  0.667  0.493  0.595  1.0
  Be  Be7  1  0.608  0.048  0.860  1.0
  Be  Be8  1  0.398  0.913  0.734  1.0
  Be  Be9  1  0.393  0.444  0.815  1.0
  Be  Be10  1  0.335  0.992  0.095  1.0
  Be  Be11  1  0.393  0.549  0.357  1.0
  Be  Be12  1  0.108  0.952  0.140  1.0
  Be  Be13  1  0.167  0.507  0.405  1.0
  Be  Be14  1  0.106  0.055  0.681  1.0
  Be  Be15  1  0.103  0.586  0.766  1.0
  F  F16  1  0.905  0.194  0.735  1.0
  F  F17  1  0.901  0.556  0.392  1.0
  F  F18  1  0.889  0.773  0.989  1.0
  F  F19  1  0.891  0.351  0.173  1.0
  F  F20  1  0.723  0.004  0.815  1.0
  F  F21  1  0.861  0.966  0.483  1.0
  F  F22  1  0.519  0.957  0.779  1.0
  F  F23  1  0.825  0.045  0.103  1.0
  F  F24  1  0.676  0.460  0.394  1.0
  F  F25  1  0.982  0.540  0.725  1.0
  F  F26  1  0.640  0.528  0.017  1.0
  F  F27  1  0.777  0.492  0.688  1.0
  F  F28  1  0.607  0.148  0.334  1.0
  F  F29  1  0.612  0.727  0.513  1.0
  F  F30  1  0.599  0.948  0.109  1.0
  F  F31  1  0.391  0.649  0.827  1.0
  F  F32  1  0.596  0.306  0.763  1.0
  F  F33  1  0.361  0.034  0.517  1.0
  F  F34  1  0.389  0.227  0.011  1.0
  F  F35  1  0.405  0.806  0.265  1.0
  F  F36  1  0.325  0.955  0.897  1.0
  F  F37  1  0.401  0.444  0.608  1.0
  F  F38  1  0.223  0.996  0.185  1.0
  F  F39  1  0.019  0.043  0.221  1.0
  F  F40  1  0.277  0.508  0.312  1.0
  F  F41  1  0.099  0.052  0.891  1.0
  F  F42  1  0.176  0.540  0.606  1.0
  F  F43  1  0.096  0.694  0.237  1.0
  F  F44  1  0.482  0.460  0.275  1.0
  F  F45  1  0.112  0.274  0.487  1.0
  F  F46  1  0.140  0.472  0.983  1.0
  F  F47  1  0.107  0.852  0.666  1.0
[/CIF]
.
The compound described by BeF2 crystallizes in the monoclinic P2_1 space group. There are eight inequivalent Be sites. In the first Be site, Be(1) is bonded to one F(1), one F(10), one F(12), and one F(2) atom to form corner-sharing BeF4 tetrahedra. In the second Be site, Be(2) is bonded to one F(1), one F(3), one F(5), and one F(8) atom to form corner-sharing BeF4 tetrahedra. In the third Be site, Be(3) is bonded in a trigonal planar geometry to one F(2), one F(3), and one F(4) atom. In the fourth Be site, Be(4) is bonded to one F(4), one F(6), one F(7), and one F(8) atom to form corner-sharing BeF4 tetrahedra. In the fifth Be site, Be(5) is bonded to one F(10), one F(11), one F(13), and one F(9) atom to form corner-sharing BeF4 tetrahedra. In the sixth Be site, Be(6) is bonded in a trigonal planar geometry to one F(13), one F(14), and one F(15) atom. In the seventh Be site, Be(7) is bonded to one F(12), one F(14), one F(16), and one F(9) atom to form corner-sharing BeF4 tetrahedra. In the eighth Be site, Be(8) is bonded to one F(15), one F(16), one F(5), and one F(7) atom to form corner-sharing BeF4 tetrahedra. There are sixteen inequivalent F sites. In the first F site, F(1) is bonded in a bent 120 degrees geometry to one Be(1) and one Be(2) atom. In the second F site, F(2) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(3) atom. In the third F site, F(3) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(3) atom. In the fourth F site, F(4) is bonded in a bent 150 degrees geometry to one Be(3) and one Be(4) atom. In the fifth F site, F(5) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(8) atom. In the sixth F site, F(6) is bonded in a single-bond geometry to one Be(4) atom. In the seventh F site, F(7) is bonded in a bent 150 degrees geometry to one Be(4) and one Be(8) atom. In the eighth F site, F(8) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(4) atom. In the ninth F site, F(9) is bonded in a bent 150 degrees geometry to one Be(5) and one Be(7) atom. In the tenth F site, F(10) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(5) atom. In the eleventh F site, F(11) is bonded in a single-bond geometry to one Be(5) atom. In the twelfth F site, F(12) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(7) atom. In the thirteenth F site, F(13) is bonded in a bent 150 degrees geometry to one Be(5) and one Be(6) atom. In the fourteenth F site, F(14) is bonded in a bent 150 degrees geometry to one Be(6) and one Be(7) atom. In the fifteenth F site, F(15) is bonded in a bent 150 degrees geometry to one Be(6) and one Be(8) atom. In the sixteenth F site, F(16) is bonded in a bent 120 degrees geometry to one Be(7) and one Be(8) atom. is represented by the CIF card [CIF]
data_BeF2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.622
_cell_length_b   6.930
_cell_length_c   7.167
_cell_angle_alpha   62.038
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   553.678
_cell_formula_units_Z   16
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
  Be  Be0  1  0.893  0.451  0.643  1.0
  Be  Be1  1  0.835  0.008  0.905  1.0
  Be  Be2  1  0.893  0.556  0.185  1.0
  Be  Be3  1  0.898  0.087  0.266  1.0
  Be  Be4  1  0.603  0.414  0.234  1.0
  Be  Be5  1  0.606  0.945  0.319  1.0
  Be  Be6  1  0.667  0.493  0.595  1.0
  Be  Be7  1  0.608  0.048  0.860  1.0
  Be  Be8  1  0.398  0.913  0.734  1.0
  Be  Be9  1  0.393  0.444  0.815  1.0
  Be  Be10  1  0.335  0.992  0.095  1.0
  Be  Be11  1  0.393  0.549  0.357  1.0
  Be  Be12  1  0.108  0.952  0.140  1.0
  Be  Be13  1  0.167  0.507  0.405  1.0
  Be  Be14  1  0.106  0.055  0.681  1.0
  Be  Be15  1  0.103  0.586  0.766  1.0
  F  F16  1  0.905  0.194  0.735  1.0
  F  F17  1  0.901  0.556  0.392  1.0
  F  F18  1  0.889  0.773  0.989  1.0
  F  F19  1  0.891  0.351  0.173  1.0
  F  F20  1  0.723  0.004  0.815  1.0
  F  F21  1  0.861  0.966  0.483  1.0
  F  F22  1  0.519  0.957  0.779  1.0
  F  F23  1  0.825  0.045  0.103  1.0
  F  F24  1  0.676  0.460  0.394  1.0
  F  F25  1  0.982  0.540  0.725  1.0
  F  F26  1  0.640  0.528  0.017  1.0
  F  F27  1  0.777  0.492  0.688  1.0
  F  F28  1  0.607  0.148  0.334  1.0
  F  F29  1  0.612  0.727  0.513  1.0
  F  F30  1  0.599  0.948  0.109  1.0
  F  F31  1  0.391  0.649  0.827  1.0
  F  F32  1  0.596  0.306  0.763  1.0
  F  F33  1  0.361  0.034  0.517  1.0
  F  F34  1  0.389  0.227  0.011  1.0
  F  F35  1  0.405  0.806  0.265  1.0
  F  F36  1  0.325  0.955  0.897  1.0
  F  F37  1  0.401  0.444  0.608  1.0
  F  F38  1  0.223  0.996  0.185  1.0
  F  F39  1  0.019  0.043  0.221  1.0
  F  F40  1  0.277  0.508  0.312  1.0
  F  F41  1  0.099  0.052  0.891  1.0
  F  F42  1  0.176  0.540  0.606  1.0
  F  F43  1  0.096  0.694  0.237  1.0
  F  F44  1  0.482  0.460  0.275  1.0
  F  F45  1  0.112  0.274  0.487  1.0
  F  F46  1  0.140  0.472  0.983  1.0
  F  F47  1  0.107  0.852  0.666  1.0
[/CIF]
.