#------------------------------------------------------------------------------
#$Date: 2010-01-30 13:59:17 +0000 (Sat, 30 Jan 2010) $
#$Revision: 966 $
#$URL: svn://www.crystallography.net/cod/cif/2/2101451.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/. The original data for this entry
# were provided by IUCr Journals, http://journals.iucr.org/.
#
# The file may be used within the scientific community so long as
# proper attribution is given to the journal article from which the
# data were obtained.
#
data_2101451
loop_
_publ_author_name
'Sarraute, S.'
'Ravez, J.'
'Von der M\"uhll, R.'
'Bravic, G.'
'Feigelson, R. S.'
'Abrahams, S. C.'
_publ_section_title
;
 Structure of ferroelectric Pb~5~Al~3~F~19~ at 160 K, polarization
 reversal and relationship to ferroelectric Pb~5~Cr~3~F~19~ at 295 K
;
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              72
_journal_page_last               77
_journal_volume                  52
_journal_year                    1996
_chemical_formula_sum            'Al3 F19 Pb5'
_chemical_formula_weight         1477.9
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'I 4 -2ab'
_symmetry_space_group_name_H-M   'I 4 c m'
_atom_type_scat_source           'IntTabIV and Cromer & Waber (1974)'
_cell_angle_alpha                90.0
_cell_angle_beta                 90.0
_cell_angle_gamma                90.0
_cell_formula_units_Z            4
_cell_length_a                   14.07(2)
_cell_length_b                   14.07(2)
_cell_length_c                   7.300(10)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    160.0(10)
_cell_measurement_theta_max      22.0
_cell_measurement_theta_min      9.0
_cell_volume                     1445(3)
_computing_cell_refinement       'CAD-4 Software (Enraf-Nonius, 1989)'
_computing_data_collection       'CAD-4 Software (Enraf-Nonius, 1989)'
_computing_data_reduction        'Local program (unpublished)'
_computing_structure_refinement
'CRYSTALS (Watkin, Carruthers & Betteridge, 1985)'
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       '\w/2\q (width 3.0 + 2.5tan\q\%)'
_diffrn_radiation_type           Mo
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.077
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4180
_diffrn_reflns_theta_max         60
_diffrn_standards_decay_%        <5
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    56.36
_exptl_absorpt_correction_T_max  0.0246
_exptl_absorpt_correction_T_min  0.0009
_exptl_absorpt_correction_type   spherical
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    6.793
_exptl_crystal_density_meas      6.660(10)
_exptl_crystal_density_method    'pycnometry at 295 K'
_exptl_crystal_description       sphere
_exptl_crystal_F_000             2480
_exptl_crystal_size_rad          0.270(10)
_refine_diff_density_max         5
_refine_diff_density_min         -6
_refine_ls_extinction_coef       'g = 31.1(11)'
_refine_ls_extinction_method     'secondary (Larson, 1970)'
_refine_ls_goodness_of_fit_obs   1.065
_refine_ls_number_parameters     71
_refine_ls_number_reflns         656
_refine_ls_R_factor_obs          0.0527
_refine_ls_shift/esd_max         0.14
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme
'w = [1/\s^2^(F)]{1-(F~o~ - F~c~)/6\s(F)]^2^}^2^'
_refine_ls_wR_factor_obs         0.0480
_reflns_number_observed          656
_reflns_number_total             742
_reflns_observed_criterion       I>3\s(I)
_[local]_cod_data_source_file    md0001.cif
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Pb1 .42602(4) .27489(4) .0 .011(2)
Pb2 .0 .5 .1350(3) .0180(10)
Al1 .1628(4) .3372 -.0210(10) .008(3)
Al2 .0 .0 .188(2) .0090(10)
F1 .1140(10) .2478(9) -.174(2) .017(2)
F2 .1970(10) .4294(8) .142(2) .0140(10)
F3 .0761(6) .4239 -.097(3) .016(2)
F4 .2479(7) .2521 .069(3) .0150(10)
F5 .0 .0 .438(2) .027(8)
F6 -.0540(10) .1175(6) .673(2) .016(2)
F7 .3835(8) .1165 .021(4) .010(5)
_cod_database_code 2101451