data_global
_chemical_name_mineral 'Preiswerkite'
loop_
_publ_author_name
'Oberti R'
'Ungaretti L'
'Tlili A'
'Smith D C'
'Robert J-L'
_journal_name_full 'American Mineralogist'
_journal_volume 78 
_journal_year 1993
_journal_page_first 1290
_journal_page_last 1298
_publ_section_title
;
 The crystal structure of preiswerkite
 Sample: KP17
;
_database_code_amcsd 0001621
_chemical_formula_sum 'Si2 Al3.15 Mg1.85 Na.85 O12 H2'
_cell_length_a 5.228
_cell_length_b 9.049
_cell_length_c 9.819
_cell_angle_alpha 90
_cell_angle_beta 100.41
_cell_angle_gamma 90
_cell_volume 456.873
_exptl_crystal_density_diffrn      2.905
_symmetry_space_group_name_H-M 'C 1 2/m 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,z'
  '1/2+x,1/2-y,z'
  '-x,y,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
  '1/2-x,1/2-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
SiT   0.57400   0.16720   0.21390   0.50000 ?
AlT   0.57400   0.16720   0.21390   0.50000 ?
Mg1   0.00000   0.50000   0.50000   0.85000 ?
Al1   0.00000   0.50000   0.50000   0.15000 ?
Mg2   0.00000   0.83020   0.50000   0.50000 ?
Al2   0.00000   0.83020   0.50000   0.50000 ?
Na   0.00000   0.00000   0.00000   0.85000 ?
O1   0.85590   0.19890   0.15840   1.00000 ?
O2   0.45300   0.00000   0.16510   1.00000 ?
O3   0.63480   0.17030   0.39050   1.00000 ?
O-h4   0.12520   0.00000   0.39890   1.00000 ?
H   0.08310   0.00000   0.29500   1.00000   0.01267
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
SiT 0.00697 0.00705 0.00236 -0.00047 0.00075 -0.00044
AlT 0.00697 0.00705 0.00236 -0.00047 0.00075 -0.00044
Mg1 0.00536 0.00456 0.00331 0.00000 0.00101 0.00000
Al1 0.00536 0.00456 0.00331 0.00000 0.00101 0.00000
Mg2 0.00656 0.00664 0.00283 0.00000 0.00101 0.00000
Al2 0.00656 0.00664 0.00283 0.00000 0.00101 0.00000
Na 0.02545 0.02489 0.00472 0.00000 0.00176 0.00000
O1 0.01259 0.01493 0.00378 0.00047 0.00277 -0.00044
O2 0.01406 0.00996 0.00331 0.00000 0.00101 0.00000
O3 0.01259 0.00996 0.00331 -0.00071 -0.00025 0.00133
O-h4 0.00951 0.03028 0.00189 0.00000 -0.00025 0.00000