data_global
_chemical_name_mineral 'Cuspidine'
loop_
_publ_author_name
'Fleet M E'
'Pan Y'
_journal_name_full 'The Canadian Mineralogist'
_journal_volume 33 
_journal_year 1995
_journal_page_first 879
_journal_page_last 884
_publ_section_title
;
 The structure of NaCa2LuSi2O7F2, a synthetic phase of the cuspidine group
;
_database_code_amcsd 0005460
_chemical_formula_sum '(Na Ca2) Lu Si2 O7 F2'
_cell_length_a 11.024
_cell_length_b 10.303
_cell_length_c 7.391
_cell_angle_alpha 90
_cell_angle_beta 109.40
_cell_angle_gamma 90
_cell_volume 791.809
_exptl_crystal_density_diffrn      4.062
_symmetry_space_group_name_H-M 'P 1 21/a 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
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
Na1   0.42470   0.12760   0.83880   0.84500   0.00849
Ca1   0.42470   0.12760   0.83880   0.15500   0.00849
Ca2   0.42620   0.13080   0.34090   0.84500   0.01241
Na2   0.42620   0.13080   0.34090   0.15500   0.01241
Lu3   0.30858   0.40160   0.52890   0.84500   0.00633
Ca3   0.30858   0.40160   0.52890   0.15500   0.00633
Ca4   0.30100   0.39570   0.02570   0.84500   0.01507
Lu4   0.30100   0.39570   0.02570   0.15500   0.01507
Si1   0.12760   0.17750   0.71980   1.00000   0.01013
Si2   0.12050   0.17690   0.15950   1.00000   0.01077
O1   0.13730   0.19370   0.95070   1.00000   0.03369
O2   0.16010   0.02890   0.69390   1.00000   0.01938
O3   0.14710   0.02480   0.20590   1.00000   0.02533
O4   0.24030   0.27260   0.71340   1.00000   0.01862
O5   0.23800   0.26810   0.28310   1.00000   0.01963
O6   0.98400   0.22150   0.59030   1.00000   0.01824
O7   0.98080   0.22620   0.12910   1.00000   0.02039
F1   0.11270   0.49160   0.44650   1.00000   0.01431
F2   0.10830   0.49490   0.93040   1.00000   0.01722