data_global
_amcsd_formula_title 'Na2MgGd2(Si4O12)F2'
loop_
_publ_author_name
'Maisonneuve V'
'LeBlanc M'
_journal_name_full 'The Canadian Mineralogist'
_journal_volume 36 
_journal_year 1998
_journal_page_first 1039
_journal_page_last 1043
_publ_section_title
;
 The crystal structure of Na2MgGd2(Si4O12)F2 and its relationship with
 leucophanite
;
_database_code_amcsd 0005553
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Gd2 Si4 Mg Na2 F2 O12'
_cell_length_a 5.178
_cell_length_b 7.510
_cell_length_c 14.381
_cell_angle_alpha 90
_cell_angle_beta 90.22
_cell_angle_gamma 90
_cell_volume 559.227
_exptl_crystal_density_diffrn      4.318
_symmetry_space_group_name_H-M 'P 1 21/c 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Gd   0.51375   0.22882   0.95706   0.00541
Si1   0.02310   0.24070   0.81400   0.00545
Si2   0.03700   0.37180   0.61490   0.00532
Mg   0.00000   0.00000   0.50000   0.00621
Na   0.50400   0.45700   0.21060   0.02394
F   0.33660   0.46070   0.06100   0.00887
O1   0.14430   0.27260   0.70980   0.00887
O2   0.71520   0.24230   0.81370   0.00887
O3   0.13900   0.04180   0.84710   0.00785
O4   0.16360   0.37330   0.88530   0.00760
O5   0.86020   0.23980   0.55350   0.00849
O6   0.28680   0.44330   0.55950   0.00861