data_2002891
_journal_name_full     'Acta Crystallographica, Section B'
_journal_year     1998
_journal_volume     B54
_journal_page_first     351
_journal_page_last     357
_publ_section_title
;
  \b-Al~4.5~FeSi: a combined synchrotron powder diffraction, electron
  diffraction, high resolution microscopy and single X-ray diffraction
  study of a faulted structure
;
loop_
    _publ_author_name
    'Hansen, Vidar'
    'Hauback, Bj\/orn'
    'Sundberg, M.'
    'R\/omming, Chr.'
    'Gj\/onnes, Jon'
_publ_section_synopsis
;
 Single crystal X-ray and electron diffraction  study of \b-Al4.5FeSi is
 confirmed and extended by synchrotron powder data and transmission electron
microscopy to include periodic faults on 001.
;
_chemical_formula_moiety     'Al4.5 Fe1 Si1'
_chemical_formula_sum     'Al4.5 Fe1 Si1'
_chemical_formula_structural     'Al4.5 Fe1 Si1'
_chemical_formula_weight     205.35
_symmetry_cell_setting     monoclinic
_symmetry_space_group_name_H-M     'A 2/a'
loop_
    _symmetry_equiv_pos_as_xyz
    '+x, +y, +z'
    '1/2-x, +y, -z'
    '+x, 1/2+y, 1/2+z'
    '1/2-x, 1/2+y, 1/2-z'
    '-x, -y, -z'
    '1/2+x, -y, +z'
    '-x, 1/2-y, 1/2-z'
    '1/2+x, 1/2-y, 1/2+z'
_cell_length_a     6.16760(10)
_cell_length_b     6.16610(10)
_cell_length_c     20.8093(3)
_cell_angle_alpha     90
_cell_angle_beta     91.000(10)
_cell_angle_gamma     90
_cell_volume     791.25(2)
_cell_formula_units_Z     8
_cell_measurement_temperature     295
_diffrn_ambient_temperature     295
_diffrn_radiation_type     'synchrotron X-ray'
_diffrn_radiation_wavelength     1.0983
_diffrn_radiation_source     ESRF
_diffrn_radiation_monochromator     'channel cut Si(111)'
_diffrn_measurement_device     'powder diffractometer SNBL, ESRF'
_diffrn_measurement_method     'Debye Scherrer mode'
_refine_ls_matrix_type     full
_refine_ls_goodness_of_fit_all     4.452
_refine_ls_number_parameters     47
_refine_ls_number_constraints     1
_refine_ls_shift/esd_max      .07
_refine_ls_shift/esd_mean      .046
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    Al Al ? ? 'GSAS library'
    Fe Fe ? ? 'GSAS library'
    Si Si ? ? 'GSAS library'
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_occupancy
    Fe  .5030(4)  .2477(4)  .13670(10)  .0214(5) 1.0
    Al1  .8608(9)  .3920(10)  .1871(3)  .0082(7) 1.0
    Al2  .6657(9)  .5843(10)  .4084(3)  .0082(7) 1.0
    Al3  .6691(9)  .5791(10)  .0939(3)  .0082(7) 1.0
    Al4  .4921(7)  .2490(12)  .0189(2)  .0082(7) 1.0
    Al5  .5  .25  .25  .0082(7) 1.0
    Al6  .8497(9)  .4033(10)  .3165(3)  .0082(7) 1.0