The crystal structure described by BeYbF4 crystallizes in the triclinic P1 space group. There are four inequivalent Be sites. In the first Be site, Be(1) is bonded to one F(12), one F(13), one F(16), and one F(7) atom to form BeF4 tetrahedra that share  a cornercorner with one Yb(1)F6 pentagonal pyramid,  a cornercorner with one Be(3)F4 tetrahedra, and  a cornercorner with one Be(4)F4 tetrahedra. In the second Be site, Be(2) is bonded in a trigonal planar geometry to one F(11), one F(2), and one F(9) atom. In the third Be site, Be(3) is bonded to one F(14), one F(16), one F(6), and one F(9) atom to form BeF4 tetrahedra that share  a cornercorner with one Yb(1)F6 pentagonal pyramid and  a cornercorner with one Be(1)F4 tetrahedra. In the fourth Be site, Be(4) is bonded to one F(1), one F(13), one F(2), and one F(5) atom to form corner-sharing BeF4 tetrahedra. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one F(10), one F(12), one F(3), one F(4), one F(6), and one F(8) atom to form distorted YbF6 pentagonal pyramids that share  a cornercorner with one Be(1)F4 tetrahedra and  a cornercorner with one Be(3)F4 tetrahedra. In the second Yb site, Yb(2) is bonded in a 6-coordinate geometry to one F(1), one F(10), one F(11), one F(14), one F(15), and one F(3) atom. In the third Yb site, Yb(3) is bonded in a 6-coordinate geometry to one F(1), one F(10), one F(15), one F(4), one F(5), and one F(8) atom. In the fourth Yb site, Yb(4) is bonded in a 7-coordinate geometry to one F(12), one F(14), one F(15), one F(3), one F(4), one F(7), and one F(8) atom. There are sixteen inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Be(4), one Yb(2), and one Yb(3) atom. In the second F site, F(2) is bonded in a water-like geometry to one Be(2) and one Be(4) atom. In the third F site, F(3) is bonded in a trigonal non-coplanar geometry to one Yb(1), one Yb(2), and one Yb(4) atom. In the fourth F site, F(4) is bonded in a trigonal non-coplanar geometry to one Yb(1), one Yb(3), and one Yb(4) atom. In the fifth F site, F(5) is bonded in a distorted water-like geometry to one Be(4) and one Yb(3) atom. In the sixth F site, F(6) is bonded in a 2-coordinate geometry to one Be(3) and one Yb(1) atom. In the seventh F site, F(7) is bonded in a distorted single-bond geometry to one Be(1) and one Yb(4) atom. In the eighth F site, F(8) is bonded in a distorted trigonal non-coplanar geometry to one Yb(1), one Yb(3), and one Yb(4) atom. In the ninth F site, F(9) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(3) atom. In the tenth F site, F(10) is bonded in a distorted trigonal non-coplanar geometry to one Yb(1), one Yb(2), and one Yb(3) atom. In the eleventh F site, F(11) is bonded in a bent 120 degrees geometry to one Be(2) and one Yb(2) atom. In the twelfth F site, F(12) is bonded in a distorted single-bond geometry to one Be(1), one Yb(1), and one Yb(4) atom. In the thirteenth F site, F(13) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(4) atom. In the fourteenth F site, F(14) is bonded in a distorted trigonal non-coplanar geometry to one Be(3), one Yb(2), and one Yb(4) atom. In the fifteenth F site, F(15) is bonded in a trigonal planar geometry to one Yb(2), one Yb(3), and one Yb(4) atom. In the sixteenth F site, F(16) is bonded in a bent 120 degrees geometry to one Be(1) and one Be(3) atom. is represented by the CIF card [CIF]
data_YbBeF4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.574
_cell_length_b   7.117
_cell_length_c   7.520
_cell_angle_alpha   103.526
_cell_angle_beta   92.591
_cell_angle_gamma   103.464
_symmetry_Int_Tables_number   1
_cell_volume   330.795
_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
  Yb  Yb0  1  0.241  0.012  0.885  1.0
  Yb  Yb1  1  0.223  0.939  0.420  1.0
  Yb  Yb2  1  0.800  0.997  0.146  1.0
  Yb  Yb3  1  0.751  0.110  0.692  1.0
  Be  Be4  1  0.794  0.591  0.615  1.0
  Be  Be5  1  0.239  0.479  0.299  1.0
  Be  Be6  1  0.410  0.358  0.605  1.0
  Be  Be7  1  0.610  0.630  0.233  1.0
  F  F8  1  0.515  0.819  0.285  1.0
  F  F9  1  0.397  0.446  0.164  1.0
  F  F10  1  0.415  0.897  0.648  1.0
  F  F11  1  0.969  0.149  0.942  1.0
  F  F12  1  0.748  0.669  0.085  1.0
  F  F13  1  0.278  0.239  0.723  1.0
  F  F14  1  0.885  0.425  0.654  1.0
  F  F15  1  0.576  0.089  0.980  1.0
  F  F16  1  0.245  0.387  0.456  1.0
  F  F17  1  0.140  0.972  0.148  1.0
  F  F18  1  0.105  0.613  0.299  1.0
  F  F19  1  0.943  0.806  0.691  1.0
  F  F20  1  0.714  0.582  0.404  1.0
  F  F21  1  0.518  0.201  0.489  1.0
  F  F22  1  0.916  0.033  0.440  1.0
  F  F23  1  0.569  0.556  0.700  1.0
[/CIF]
.
The crystal structure described by BeYbF4 crystallizes in the triclinic P1 space group. There are four inequivalent Be sites. In the first Be site, Be(1) is bonded to one F(12), one F(13), one F(16), and one F(7) atom to form BeF4 tetrahedra that share  a cornercorner with one Yb(1)F6 pentagonal pyramid,  a cornercorner with one Be(3)F4 tetrahedra, and  a cornercorner with one Be(4)F4 tetrahedra. In the second Be site, Be(2) is bonded in a trigonal planar geometry to one F(11), one F(2), and one F(9) atom. In the third Be site, Be(3) is bonded to one F(14), one F(16), one F(6), and one F(9) atom to form BeF4 tetrahedra that share  a cornercorner with one Yb(1)F6 pentagonal pyramid and  a cornercorner with one Be(1)F4 tetrahedra. In the fourth Be site, Be(4) is bonded to one F(1), one F(13), one F(2), and one F(5) atom to form corner-sharing BeF4 tetrahedra. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to one F(10), one F(12), one F(3), one F(4), one F(6), and one F(8) atom to form distorted YbF6 pentagonal pyramids that share  a cornercorner with one Be(1)F4 tetrahedra and  a cornercorner with one Be(3)F4 tetrahedra. In the second Yb site, Yb(2) is bonded in a 6-coordinate geometry to one F(1), one F(10), one F(11), one F(14), one F(15), and one F(3) atom. In the third Yb site, Yb(3) is bonded in a 6-coordinate geometry to one F(1), one F(10), one F(15), one F(4), one F(5), and one F(8) atom. In the fourth Yb site, Yb(4) is bonded in a 7-coordinate geometry to one F(12), one F(14), one F(15), one F(3), one F(4), one F(7), and one F(8) atom. There are sixteen inequivalent F sites. In the first F site, F(1) is bonded in a distorted single-bond geometry to one Be(4), one Yb(2), and one Yb(3) atom. In the second F site, F(2) is bonded in a water-like geometry to one Be(2) and one Be(4) atom. In the third F site, F(3) is bonded in a trigonal non-coplanar geometry to one Yb(1), one Yb(2), and one Yb(4) atom. In the fourth F site, F(4) is bonded in a trigonal non-coplanar geometry to one Yb(1), one Yb(3), and one Yb(4) atom. In the fifth F site, F(5) is bonded in a distorted water-like geometry to one Be(4) and one Yb(3) atom. In the sixth F site, F(6) is bonded in a 2-coordinate geometry to one Be(3) and one Yb(1) atom. In the seventh F site, F(7) is bonded in a distorted single-bond geometry to one Be(1) and one Yb(4) atom. In the eighth F site, F(8) is bonded in a distorted trigonal non-coplanar geometry to one Yb(1), one Yb(3), and one Yb(4) atom. In the ninth F site, F(9) is bonded in a bent 150 degrees geometry to one Be(2) and one Be(3) atom. In the tenth F site, F(10) is bonded in a distorted trigonal non-coplanar geometry to one Yb(1), one Yb(2), and one Yb(3) atom. In the eleventh F site, F(11) is bonded in a bent 120 degrees geometry to one Be(2) and one Yb(2) atom. In the twelfth F site, F(12) is bonded in a distorted single-bond geometry to one Be(1), one Yb(1), and one Yb(4) atom. In the thirteenth F site, F(13) is bonded in a bent 150 degrees geometry to one Be(1) and one Be(4) atom. In the fourteenth F site, F(14) is bonded in a distorted trigonal non-coplanar geometry to one Be(3), one Yb(2), and one Yb(4) atom. In the fifteenth F site, F(15) is bonded in a trigonal planar geometry to one Yb(2), one Yb(3), and one Yb(4) atom. In the sixteenth F site, F(16) is bonded in a bent 120 degrees geometry to one Be(1) and one Be(3) atom. is represented by the CIF card [CIF]
data_YbBeF4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.574
_cell_length_b   7.117
_cell_length_c   7.520
_cell_angle_alpha   103.526
_cell_angle_beta   92.591
_cell_angle_gamma   103.464
_symmetry_Int_Tables_number   1
_cell_volume   330.795
_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
  Yb  Yb0  1  0.241  0.012  0.885  1.0
  Yb  Yb1  1  0.223  0.939  0.420  1.0
  Yb  Yb2  1  0.800  0.997  0.146  1.0
  Yb  Yb3  1  0.751  0.110  0.692  1.0
  Be  Be4  1  0.794  0.591  0.615  1.0
  Be  Be5  1  0.239  0.479  0.299  1.0
  Be  Be6  1  0.410  0.358  0.605  1.0
  Be  Be7  1  0.610  0.630  0.233  1.0
  F  F8  1  0.515  0.819  0.285  1.0
  F  F9  1  0.397  0.446  0.164  1.0
  F  F10  1  0.415  0.897  0.648  1.0
  F  F11  1  0.969  0.149  0.942  1.0
  F  F12  1  0.748  0.669  0.085  1.0
  F  F13  1  0.278  0.239  0.723  1.0
  F  F14  1  0.885  0.425  0.654  1.0
  F  F15  1  0.576  0.089  0.980  1.0
  F  F16  1  0.245  0.387  0.456  1.0
  F  F17  1  0.140  0.972  0.148  1.0
  F  F18  1  0.105  0.613  0.299  1.0
  F  F19  1  0.943  0.806  0.691  1.0
  F  F20  1  0.714  0.582  0.404  1.0
  F  F21  1  0.518  0.201  0.489  1.0
  F  F22  1  0.916  0.033  0.440  1.0
  F  F23  1  0.569  0.556  0.700  1.0
[/CIF]
.