data_global
_chemical_name_mineral 'Povondraite'
loop_
_publ_author_name
'Grice J D'
'Ercit T S'
'Hawthorne F C'
_journal_name_full 'American Mineralogist'
_journal_volume 78 
_journal_year 1993
_journal_page_first 433
_journal_page_last 436
_publ_section_title
;
 Povondraite, a redefinition of the tourmaline ferridravite
 Note: Atomic parameters updated by Grice on 11/20/2001
;
_database_code_amcsd 0001555
_chemical_compound_source 'San Francisco mine, Villa Tunari, Bolivia'
_chemical_formula_sum '(Na.8 K.2) Fe6.87 Mg1.83 Al.3 Si6 B3 O31 H3.12'
_cell_length_a 16.186
_cell_length_b 16.186
_cell_length_c 7.444
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1688.947
_exptl_crystal_density_diffrn      3.429
_symmetry_space_group_name_H-M 'R 3 m'
loop_
_space_group_symop_operation_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
_atom_site_U_iso_or_equiv
NaX   0.00000   0.00000   0.22770   0.80000   0.02300
KX   0.00000   0.00000   0.22770   0.20000   0.02300
FeY   0.12240   0.06120   0.64290   0.85000   0.00650
MgY   0.12240   0.06120   0.64290   0.15000   0.00650
FeZ   0.29870   0.26270   0.61240   0.72000   0.00580
MgZ   0.29870   0.26270   0.61240   0.23000   0.00580
AlZ   0.29870   0.26270   0.61240   0.05000   0.00580
SiT   0.18920   0.18760   0.00000   1.00000   0.00600
B   0.10970   0.21940   0.45580   1.00000   0.00950
O1   0.00000   0.00000   0.77180   0.88000   0.00700
O-H1   0.00000   0.00000   0.77180   0.12000   0.00700
O2   0.06100   0.12200   0.49050   1.00000   0.01000
O3   0.25780   0.12890   0.51230   1.00000   0.00900
O4   0.09240   0.18480   0.06920   1.00000   0.01100
O5   0.18260   0.09130   0.08660   1.00000   0.01000
O6   0.19220   0.18290   0.78380   1.00000   0.00800
O7   0.28110   0.28130   0.07540   1.00000   0.01000
O8   0.20700   0.26790   0.44200   1.00000   0.01000
H3   0.24110   0.12050   0.40270   1.00000   0.02000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
NaX 0.01710 0.01710 0.03400 0.00855 0.00000 0.00000
KX 0.01710 0.01710 0.03400 0.00855 0.00000 0.00000
FeY 0.00440 0.00360 0.01180 0.00220 -0.00090 -0.00050
MgY 0.00440 0.00360 0.01180 0.00220 -0.00090 -0.00050
FeZ 0.00410 0.00410 0.00910 0.00210 0.00050 0.00090
MgZ 0.00410 0.00410 0.00910 0.00210 0.00050 0.00090
AlZ 0.00410 0.00410 0.00910 0.00210 0.00050 0.00090
SiT 0.00560 0.00430 0.00970 0.00280 -0.00100 -0.00100
B 0.01180 0.00460 0.00780 0.00230 0.00030 0.00060
O1 0.00770 0.00770 0.00770 0.00385 0.00000 0.00000
O-H1 0.00770 0.00770 0.00770 0.00385 0.00000 0.00000
O2 0.01010 0.00410 0.01300 0.00200 0.00090 0.00180
O3 0.01220 0.00770 0.00880 0.00610 -0.00260 -0.00130
O4 0.00820 0.01560 0.01260 0.00780 -0.00580 -0.00290
O5 0.01020 0.00400 0.01830 0.00510 0.00050 0.00020
O6 0.01140 0.00690 0.00830 0.00570 -0.00040 -0.00160
O7 0.00860 0.00680 0.01190 0.00200 -0.00020 -0.00090
O8 0.00530 0.00970 0.01750 0.00450 0.00380 0.00550