data_global
_chemical_name_mineral 'Londonite'
loop_
_publ_author_name
'Gatta G D'
'Vignola P'
'McIntyre G J'
'Diella V'
_journal_name_full 'American Mineralogist'
_journal_volume 95 
_journal_year 2010
_journal_page_first 1467
_journal_page_last 1472
_publ_section_title
;
 On the crystal chemistry of londonite [(Cs,K,Rb)Al4Be5B11O28]:
 a single-crystal neutron diffraction study at 300 and 20 K
 Note: neutron diffraction study at T = 20 K
;
_database_code_amcsd 0017718
_chemical_compound_source 'Antsongombato Gem mine, Betafo district, Madagascar'
_chemical_formula_sum 'Cs.34 K.34 Rb.17 Al4 (Be5.32 B10.68) O28'
_cell_length_a 7.3094
_cell_length_b 7.3094
_cell_length_c 7.3094
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 390.522
_exptl_crystal_density_diffrn      3.369
_symmetry_space_group_name_H-M 'P -4 3 m'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-z,x,-y'
  '-y,z,-x'
  '-x,y,-z'
  'x,-z,-y'
  'z,-y,-x'
  'y,-x,-z'
  'x,z,y'
  'z,y,x'
  'y,x,z'
  '-z,-x,y'
  '-y,-z,x'
  '-x,-y,z'
  'z,-x,-y'
  'y,-z,-x'
  'x,-y,-z'
  '-x,z,-y'
  '-z,y,-x'
  '-y,x,-z'
  '-x,-z,y'
  '-z,-y,x'
  '-y,-x,z'
  'z,x,y'
  'y,z,x'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
Cs   0.00000   0.00000   0.00000   0.34000   0.01000
K   0.00000   0.00000   0.00000   0.34000   0.01000
Rb   0.00000   0.00000   0.00000   0.17000   0.01000
Al   0.36030   0.36030   0.36030   1.00000   0.00120
Be1   0.24846   0.50000   0.00000   0.12000   0.00120
B1   0.24846   0.50000   0.00000   0.88000   0.00120
Be2   0.74190   0.25810   0.25810   0.97000   0.00120
B2   0.74190   0.25810   0.25810   0.03000   0.00120
O1   0.38070   0.61930   0.38070   1.00000   0.00120
O2   0.36390   0.36390   0.10010   1.00000   0.00190
O3   0.39899   0.86510   0.13490   1.00000   0.00240
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
O2 0.00210 0.00210 0.00140 0.00090 0.00040 0.00040
O3 0.00230 0.00250 0.00250 -0.00010 0.00010 0.00020