data_global
_chemical_name_mineral 'Nyerereite'
loop_
_publ_author_name
'McKie D'
'Frankis E J'
_journal_name_full 'Zeitschrift fur Kristallographie'
_journal_volume 145 
_journal_year 1977
_journal_page_first 73
_journal_page_last 95
_publ_section_title
;
 Nyerereite: A new volcanic carbonate mineral from Oldoinyo Lengai, Tanzania
 Note: low-temperature polymorph that inverted from the high-temperature polymorph
 Note: only half of the O atoms have been located
;
_database_code_amcsd 0010790
_chemical_compound_source 'Oldoinyo Lengai, Tanzania'
_chemical_formula_sum 'Ca Na1.64 K.36 C2 O3'
_cell_length_a 5.044
_cell_length_b 8.809
_cell_length_c 12.743
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 566.205
_exptl_crystal_density_diffrn      1.922
_symmetry_space_group_name_H-M 'C m c 21'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,1/2+z'
  '1/2+x,1/2-y,1/2+z'
  '-x,y,z'
  '1/2-x,1/2+y,z'
  '-x,-y,1/2+z'
  '1/2-x,1/2-y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Ca   0.00000   0.98000   0.00000   1.00000
Na1   0.00000   0.32000   0.82000   0.64000
K1   0.00000   0.32000   0.82000   0.36000
Na2   0.00000   0.32000   0.12000   1.00000
C1   0.00000   0.35000   0.51000   1.00000
C2   0.00000   0.99000   0.23000   1.00000
O1   0.22000   0.28000   0.52000   1.00000
O2   0.00000   0.49000   0.49000   1.00000