data_global
_chemical_name_mineral 'Birnessite'
loop_
_publ_author_name
'Lanson B'
'Drits V A'
'Feng Q'
'Manceau A'
_journal_name_full 'American Mineralogist'
_journal_volume 87 
_journal_year 2002
_journal_page_first 1662
_journal_page_last 1671
_publ_section_title
;
 Structure of synthetic Na-rich birnessite: Evidence for a triclinic
 one-layer unit cell
;
_database_code_amcsd 0002932
_chemical_formula_sum 'Mn.5 O2.544 Na.364 H1.088'
_cell_length_a 2.9513
_cell_length_b 2.9547
_cell_length_c 7.334
_cell_angle_alpha 78.72
_cell_angle_beta 101.79
_cell_angle_gamma 122.33
_cell_volume 52.611
_exptl_crystal_density_diffrn      2.450
_symmetry_space_group_name_H-M 'P -1'
loop_
_space_group_symop_operation_xyz
  'x,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
Mn-layer   0.00000   0.00000   0.00000   0.50000   0.00633
O-layer   0.38860  -0.37330   0.13960   1.00000   0.01267
Na-Int   0.62800   0.47600   0.48100   0.18200   0.02533
Wat-Int   0.29000  -0.81900   0.49600   0.27200   0.02533