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: Ni60
;
_database_code_amcsd 0001878
_chemical_formula_sum 'Si8 (Mg1.95 Ni3.05) Ca1.07 Na2.79 O24'
_cell_length_a 9.8956
_cell_length_b 17.948
_cell_length_c 5.2567
_cell_angle_alpha 90
_cell_angle_beta 104.413
_cell_angle_gamma 90
_cell_volume 904.239
_exptl_crystal_density_diffrn      3.460
_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   0.28110   0.08570   0.29790   1.00000
Si2   0.28570   0.16940   0.79900   1.00000
Mg1   0.00000   0.08850   0.50000   0.30000
Ni1   0.00000   0.08850   0.50000   0.70000
Mg2   0.00000   0.17770   0.00000   0.55000
Ni2   0.00000   0.17770   0.00000   0.45000
Mg3   0.00000   0.00000   0.00000   0.25000
Ni3   0.00000   0.00000   0.00000   0.75000
Ca4   0.00000   0.27450   0.50000   0.53500
Na4   0.00000   0.27450   0.50000   0.46500
NaA   0.00000   0.48120   0.00000   0.93000
O1   0.11320   0.08750   0.22110   1.00000
O2   0.11100   0.16810   0.72290   1.00000
O3   0.10660   0.00000   0.70670   1.00000
O4   0.35840   0.24810   0.77390   1.00000
O5   0.34550   0.13000   0.09140   1.00000
O6   0.34350   0.11210   0.59890   1.00000
O7   0.34150   0.00000   0.30700   1.00000