data_9007647
_chemical_name 'Cryptomelane'
loop_
_publ_author_name
'Post J E'
'Von Dreele R B'
'Buseck P R'
_journal_name_full "Acta Crystallographica, Section B"
_journal_volume 38
_journal_year 1982
_journal_page_first 1056
_journal_page_last 1065
_publ_section_title
;
 Symmetry and cation displacements in hollandites:
 structure refinements of hollandite, cryptomelane and priderite
 Locality: Chindwara, India
 Note: -1M polytype
 Note: Anisotropic displacement factors from ICSD
;
_chemical_formula_sum 'K.65 Na.11 Sr.08 Mn3.76 Fe.16 Al.08 O8'
_cell_length_a 9.956
_cell_length_b 2.8705
_cell_length_c 9.706
_cell_angle_alpha 90
_cell_angle_beta 90.95
_cell_angle_gamma 90
_cell_volume 277.347
_symmetry_space_group_name_H-M 'I 1 2/m 1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+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'
  '-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_occupancy
_atom_site_Uiso_or_equiv
K   0.00000   0.00000   0.00000   0.65000   0.02600
Na   0.00000   0.50000   0.00000   0.11000   0.03000
Sr   0.00000   0.18500   0.00000   0.04000   0.02000
Mn4+1   0.85145   0.00000   0.33185   0.79000   0.00440
Mn3+1   0.85145   0.00000   0.33185   0.15000   0.00440
Fe1   0.85145   0.00000   0.33185   0.04000   0.00440
Al1   0.85145   0.00000   0.33185   0.02000   0.00440
Mn4+2   0.33546   0.00000   0.15305   0.79000   0.00430
Mn3+2   0.33546   0.00000   0.15305   0.15000   0.00430
Fe2   0.33546   0.00000   0.15305   0.04000   0.00430
Al2   0.33546   0.00000   0.15305   0.02000   0.00430
O1   0.65720   0.00000   0.30190   1.00000   0.00680
O2   0.65610   0.00000   0.04200   1.00000   0.00700
O3   0.29470   0.00000   0.34990   1.00000   0.00680
O4   0.04230   0.00000   0.32490   1.00000   0.00720