data_global
_chemical_name_mineral 'Muscovite-2M1'
loop_
_publ_author_name
'Martin-Ramos JD'
'Rodriguez-Gallego M'
_journal_name_full 'Mineralogical Magazine'
_journal_volume 46 
_journal_year 1982
_journal_page_first 269
_journal_page_last 272
_publ_section_title
;
 Chromian mica from Sierra Nevada, Spain
 Note: y-coordinates of T2 and M1 sites altered
;
_database_code_amcsd 0014475
_chemical_compound_source 'Sierra Nevada, Spain'
_chemical_formula_sum 'K.69 Na.06 Ca.13 Al2.14 Cr.16 Mg.54 Fe.08 Si3.08 O11.9 H1.9'
_cell_length_a 5.2116
_cell_length_b 9.045
_cell_length_c 19.97
_cell_angle_alpha 90
_cell_angle_beta 95.7
_cell_angle_gamma 90
_cell_volume 936.710
_exptl_crystal_density_diffrn      2.808
_symmetry_space_group_name_H-M 'C 1 2/c 1'
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,1/2-z'
  '1/2-x,1/2+y,1/2-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
K   0.00000   0.09670   0.25000   0.69000   0.02457
Na   0.00000   0.09670   0.25000   0.06000   0.02457
Ca   0.00000   0.09670   0.25000   0.13000   0.02457
Al1   0.24890   0.08260   0.00010   0.61000   0.00811
Cr1   0.24890   0.08260   0.00010   0.08000   0.00811
Mg1   0.24890   0.08260   0.00010   0.27000   0.00811
Fe1   0.24890   0.08260   0.00010   0.04000   0.00811
AlT1   0.96350   0.42960   0.13530   0.23000   0.00709
SiT1   0.96350   0.42960   0.13530   0.77000   0.00709
AlT2   0.45170   0.25890   0.13550   0.23000   0.00798
SiT2   0.45170   0.25890   0.13550   0.77000   0.00798
O1   0.95580   0.43860   0.05460   1.00000   0.01381
O2   0.39350   0.25290   0.05460   1.00000   0.01267
O3   0.43900   0.09340   0.16920   1.00000   0.01634
O4   0.73850   0.32340   0.16030   1.00000   0.01862
O5   0.23840   0.36110   0.16940   1.00000   0.01431
O-H   0.95470   0.06540   0.05150   0.95000   0.01456