data_9001513
_chemical_name 'Dravite'
loop_
_publ_author_name
'Hawthorne F C'
'MacDonald D J'
'Burns P C'
_journal_name_full "American Mineralogist"
_journal_volume 78
_journal_year 1993
_journal_page_first 265
_journal_page_last 270
_publ_section_title
;
 Reassignment of cation site occupancies in tourmaline: Al-Mg disorder in the
 crystal structure of dravite
;
_chemical_formula_sum 'Na.814 K.014 Ca.009 Ti.03 Cr.006 Fe.612 Mn.003 Mg2.274 Al
_cell_length_a 15.947
_cell_length_b 15.947
_cell_length_c 7.214
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1588.783
_symmetry_space_group_name_H-M 'R 3 m'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'x,x-y,z'
  '2/3+x,1/3+x-y,1/3+z'
  '1/3+x,2/3+x-y,2/3+z'
  '-y,-x,z'
  '2/3-y,1/3-x,1/3+z'
  '1/3-y,2/3-x,2/3+z'
  '-x+y,y,z'
  '2/3-x+y,1/3+y,1/3+z'
  '1/3-x+y,2/3+y,2/3+z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
NaX   0.00000   0.00000   0.15920   0.81400
KX   0.00000   0.00000   0.15920   0.01400
CaX   0.00000   0.00000   0.15920   0.00900
TiY   0.93867   0.06133   0.56430   0.01000
CrY   0.93867   0.06133   0.56430   0.00200
FeY   0.93867   0.06133   0.56430   0.20400
MnY   0.93867   0.06133   0.56430   0.00100
MgY   0.93867   0.06133   0.56430   0.45000
AlY   0.93867   0.06133   0.56430   0.33400
AlZ   0.73849   0.70217   0.53860   0.84600
MgZ   0.73849   0.70217   0.53860   0.15400
Si   0.81018   0.80835   0.92800   1.00000
B   0.11000   0.89000   0.38190   1.00000
O1   0.00000   0.00000   0.69890   1.00000
O2   0.06109   0.93891   0.41560   1.00000
O3   0.86947   0.13053   0.43810   1.00000
O4   0.09300   0.90601   0.99890   1.00000
O5   0.90733   0.09267   0.02120   1.00000
O6   0.81568   0.80578   0.70590   1.00000
O7   0.71512   0.71494   0.00590   1.00000
O8   0.73016   0.79077   0.36740   1.00000