data_global
_chemical_name_mineral 'Richterite'
loop_
_publ_author_name
'Della Ventura G'
'Robert J-L'
'Raudsepp M'
'Hawthorne F C'
'Welch M D'
_journal_name_full 'American Mineralogist'
_journal_volume 82 
_journal_year 1997
_journal_page_first 291
_journal_page_last 301
_publ_section_title
;
 Site occupancies in synthetic monoclinic amphiboles: Rietveld structure
 refinement and infrared spectroscopy of (nickel, magnesium, cobalt)-richterite
 Sample: Ni100
;
_database_code_amcsd 0001880
_chemical_formula_sum 'Si8 Ni5 Ca1.02 Na2.98 O24'
_cell_length_a 9.8927
_cell_length_b 17.926
_cell_length_c 5.2534
_cell_angle_alpha 90
_cell_angle_beta 104.480
_cell_angle_gamma 90
_cell_volume 902.027
_exptl_crystal_density_diffrn      3.724
_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
Si1   0.27950   0.08570   0.29780   1.00000
Si2   0.28790   0.17020   0.80650   1.00000
Ni1   0.00000   0.08820   0.50000   1.00000
Ni2   0.00000   0.17680   0.00000   1.00000
Ni3   0.00000   0.00000   0.00000   1.00000
Ca4   0.00000   0.27410   0.50000   0.51000
Na4   0.00000   0.27410   0.50000   0.49000
NaA   0.00000   0.47830   0.00000   1.00000
O1   0.11110   0.08620   0.21410   1.00000
O2   0.11520   0.16890   0.72720   1.00000
O3   0.10670   0.00000   0.71020   1.00000
O4   0.35810   0.24760   0.77720   1.00000
O5   0.34750   0.13070   0.10230   1.00000
O6   0.34000   0.11220   0.59990   1.00000
O7   0.34240   0.00000   0.30000   1.00000