data_global
_chemical_name_mineral 'Chevkinite-(Nd)'
loop_
_publ_author_name
'Calvo C'
'Faggiani R'
_journal_name_full 'American Mineralogist'
_journal_volume 59
_journal_year 1974
_journal_page_first 1277
_journal_page_last 1285
_publ_section_title
;
 A re-investigation of the crystal structures of chevkinite and perrierite
;
_database_code_amcsd 434
_chemical_compound_source 'natural, but location not given'
_chemical_formula_sum 'Nd4 Si4 Co2 Ti3 O22'
_cell_length_a 13.325
_cell_length_b 5.706
_cell_length_c 10.998
_cell_angle_alpha 90.0
_cell_angle_beta 100.82
_cell_angle_gamma 90.0
_cell_volume 821.339
_exptl_crystal_density_diffrn  5.268
_symmetry_space_group_name_H-M 'P 1 21/a 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,z'
  '1/2-x,1/2+y,-z'
  '-x,-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
Nd1   0.35651  0.01889  0.23426  1.0  0.0099
Nd2   0.06955  -0.03317  0.24116  1.0  0.0089
Si1   0.2008  0.4974  0.2298  1.0  0.0053
Si2   0.3584  0.4993  0.0464  1.0  0.0063
Co   0.0  0.5  0.0  1.0  0.0093
Ti1   0.2447  0.2456  0.5003  0.68  0.0106
Co1   0.2447  0.2456  0.5003  0.32  0.0106
Ti2a   0.0  0.5  0.5  0.82  0.0119
Co2a   0.0  0.5  0.5  0.18  0.0119
Ti2b   0.5  0.5  0.5  0.82  0.0129
Co2b   0.5  0.5  0.5  0.18  0.0129
O1   0.2384  -0.2725  0.3137  1.0  0.007
O11   0.2183  0.2595  0.3126  1.0  0.007
O21   -0.0254  0.2515  0.3721  1.0  0.008
O2   -0.0241  -0.2575  0.3697  1.0  0.012
O3   0.4134  -0.255  0.0957  1.0  0.012
O31   0.4402  0.288  0.0954  1.0  0.013
O5   0.1516  0.4959  0.5092  1.0  0.008
O4   0.145  -0.0121  0.4752  1.0  0.007
O6   0.0833  0.5434  0.1737  1.0  0.01
O7   0.2705  0.4515  0.1247  1.0  0.013
O8   0.3149  -0.0097  -0.0992  1.0  0.011