data_global
_chemical_name_mineral 'Windhoekite'
loop_
_publ_author_name
'Chukanov N V'
'Britvin S N'
'Blass G'
'Belakovskiy D I'
'Van K V'
_journal_name_full 'European Journal of Mineralogy'
_journal_volume 24 
_journal_year 2012
_journal_page_first 171
_journal_page_last 179
_publ_section_title
;
 Windhoekite, Ca2Fe3+3-x(Si8O20)(OH)4*10H2O, a new palygorskite-group mineral
 from the Aris phonolite, Namibia
 Note: the chemical formula for this mineral cannot be obtained from the
 crystal structure. The structure is missing two oxygens, and
 the OH positions were not given.
;
_database_code_amcsd 0018919
_chemical_compound_source 'Aris phonolite, Namibia'
_chemical_formula_sum 'Ca1.98 Mn.14 Fe2.76 Si8 O32 H20'
_cell_length_a 14.319
_cell_length_b 17.825
_cell_length_c 5.242
_cell_angle_alpha 90
_cell_angle_beta 103.5
_cell_angle_gamma 90
_cell_volume 1300.980
_exptl_crystal_density_diffrn      2.548
_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
CaM3   0.50000   0.31300   0.00000   0.62000   0.05700
Mn2+M3   0.50000   0.31300   0.00000   0.04000   0.05700
CaM4   0.50000   0.23000   0.50000   0.37000   0.05300
Mn2+M4   0.50000   0.23000   0.50000   0.03000   0.05300
Fe3+M1   0.50000   0.50000   0.00000   1.00000   0.02940
Fe3+M2   0.50000   0.41260   0.50000   0.88000   0.03010
Si1   0.30010   0.41620   0.03140   1.00000   0.02220
Si2   0.29870   0.33130   0.52620   1.00000   0.02720
O1   0.41800   0.41670   0.11440   1.00000   0.02600
O2   0.41540   0.33080   0.59100   1.00000   0.03600
O3   0.25000   0.25000   0.50000   1.00000   0.04100
O4   0.56850   0.50000   0.36440   1.00000   0.03300
O5   0.25760   0.50000   0.00150   1.00000   0.03100
O6   0.25660   0.37350   0.24950   1.00000   0.03100
O7   0.25980   0.37450   0.75500   1.00000   0.03200
Wat1   0.10600   0.50000   0.36100   1.00000   0.26000
Wat2   0.40640   0.23020   0.10700   1.00000   0.13200
Wat3   0.48700   0.10600   0.69800   1.00000   0.87000
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
CaM3 0.06300 0.06700 0.04300 0.00000 0.01900 0.00000
Mn2+M3 0.06300 0.06700 0.04300 0.00000 0.01900 0.00000
CaM4 0.06500 0.04500 0.05000 0.00000 0.01600 0.00000
Mn2+M4 0.06500 0.04500 0.05000 0.00000 0.01600 0.00000
Fe3+M1 0.05000 0.02400 0.01800 0.00000 0.01500 0.00000
Fe3+M2 0.05100 0.02300 0.02200 0.00000 0.01900 0.00000
Si1 0.04500 0.01000 0.01600 -0.00340 0.01500 -0.00110
Si2 0.05300 0.01000 0.02400 -0.00300 0.02000 -0.00010
O1 0.04400 0.01200 0.02500 -0.00700 0.01600 -0.00200
O2 0.05200 0.02300 0.03700 -0.00100 0.01700 -0.00300
O3 0.09200 0.00900 0.02900 -0.01700 0.02600 0.00500
O4 0.04300 0.03300 0.03300 0.00000 0.02800 0.00000
O5 0.05700 0.00800 0.03100 0.00000 0.01900 0.00000
O6 0.06100 0.01800 0.01900 -0.00100 0.02200 0.00600
O7 0.05700 0.00900 0.03500 -0.00900 0.02300 -0.00600
Wat1 0.27000 0.27000 0.33000 0.00000 0.24000 0.00000
Wat2 0.17000 0.12000 0.13000 0.01900 0.08300 -0.01000