data_global
_chemical_name_mineral 'Moganite'
loop_
_publ_author_name
'Heaney P J'
'Post J E'
_journal_name_full 'American Mineralogist'
_journal_volume 86 
_journal_year 2001
_journal_page_first 1358
_journal_page_last 1366
_publ_section_title
;
 Evidence for an I2/a to Imab phase transition in the silica
 polymorph moganite at ~570 K
 Sample: T = 1354 K
;
_database_code_amcsd 0002738
_chemical_formula_sum 'Si O2'
_cell_length_a 8.8159
_cell_length_b 4.9371
_cell_length_c 10.7605
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 468.351
_exptl_crystal_density_diffrn      2.556
_symmetry_space_group_name_H-M 'I m a b'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,1/2+z'
  '1/2+x,y,-z'
  '+x,1/2+y,1/2-z'
  '1/2-x,-y,z'
  '-x,1/2-y,1/2+z'
  'x,-y,-z'
  '1/2+x,1/2-y,1/2-z'
  '-x,y,z'
  '1/2-x,1/2+y,1/2+z'
  '1/2-x,y,-z'
  '-x,1/2+y,1/2-z'
  '1/2+x,-y,z'
  '+x,1/2-y,1/2+z'
  '-x,-y,-z'
  '1/2-x,1/2-y,1/2-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Si1   0.25000   0.00000   0.00000   0.03000
Si2   0.00000   0.22550   0.17010   0.03000
O1   0.00000   0.04160   0.29350   0.03000
O2   0.14710   0.20070   0.08240   0.03000