data_global
_chemical_name_mineral 'Richterite'
loop_
_publ_author_name
'Della Ventura G'
'Robert J-L'
'Raudsepp M'
'Hawthorne F C'
_journal_name_full 'American Mineralogist'
_journal_volume 78 
_journal_year 1993
_journal_page_first 633
_journal_page_last 640
_publ_section_title
;
 Site occupancies in monoclinic amphiboles: Rietveld structure refinement of
 synthetic magnesium cobalt potassium richterite
 Sample: KNi0
 Atomic parameters from ICSD
;
_database_code_amcsd 0001574
_chemical_formula_sum 'Si8 Mg5 (Na Ca) K O24 H2'
_cell_length_a 10.0547
_cell_length_b 17.997
_cell_length_c 5.2746
_cell_angle_alpha 90
_cell_angle_beta 104.832
_cell_angle_gamma 90
_cell_volume 922.660
_exptl_crystal_density_diffrn      3.003
_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
Si1   0.27610   0.08590   0.30130   1.00000   0.00507
Si2   0.28430   0.17100   0.80240   1.00000   0.00507
Mg1   0.00000   0.08950   0.50000   1.00000   0.00760
Mg2   0.00000   0.17980   0.00000   1.00000   0.00760
Mg3   0.00000   0.00000   0.00000   1.00000   0.00760
Na   0.00000   0.27610   0.50000   0.50000   0.01140
Ca   0.00000   0.27610   0.50000   0.50000   0.01140
K   0.02130   0.50000   0.02780   0.50000   0.02913
O1   0.10790   0.08800   0.21490   1.00000   0.01013
O2   0.11360   0.17160   0.71760   1.00000   0.01013
O-H3   0.10780   0.00000   0.72360   1.00000   0.01013
O4   0.35420   0.24860   0.78540   1.00000   0.01013
O5   0.33450   0.13000   0.09450   1.00000   0.01393
O6   0.33990   0.11590   0.60300   1.00000   0.01393
O7   0.32710   0.00000   0.30720   1.00000   0.01520