data_global
_chemical_name_mineral 'Barstowite'
loop_
_publ_author_name
'Kutzke H'
'Klapper H'
'Merlino S'
'Pasero M'
'Perchiazzi N'
'Eggert G'
_journal_name_full 'Zeitschrift fur Kristallographie'
_journal_volume 215 
_journal_year 2000
_journal_page_first 110
_journal_page_last 113
_publ_section_title
;
 The crystal structure of barstowite, Pb4Cl6(CO3)*H2O, determined on
 crystals from Etruscan slags and from a Late-Hellenistic shipwreck
;
_database_code_amcsd 0019157
_chemical_compound_source 'a Late-Hellenistic shipwreck found near Mahdia, Tunisia'
_chemical_formula_sum 'Pb4 Cl6 C O4 H2'
_cell_length_a 4.2043
_cell_length_b 9.199
_cell_length_c 16.663
_cell_angle_alpha 90
_cell_angle_beta 91.82
_cell_angle_gamma 90
_cell_volume 644.122
_exptl_crystal_density_diffrn      5.772
_symmetry_space_group_name_H-M 'P 1 21/m 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,z'
  '-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_U_iso_or_equiv
Pb1   0.23950   0.25000   0.45859   0.02850
Pb2   0.24560   0.25000   0.98843   0.03040
Pb3   0.69040   0.00959   0.23182   0.02014
Cl1   0.21200   0.25000   0.28120   0.01646
Cl2   0.75700   0.25000   0.10400   0.01520
Cl3   0.26020   0.94910   0.08610   0.02026
Cl4   0.73190   0.03100   0.41200   0.01773
C   0.91000   0.25000   0.74500   0.01267
O1   0.17500   0.25000   0.78620   0.01520
O2   0.79400   0.12700   0.72280   0.01520
Wat3   0.74900   0.25000   0.56720   0.02280