#------------------------------------------------------------------------------
#$Date: 2016-03-23 01:58:35 +0200 (Wed, 23 Mar 2016) $
#$Revision: 179164 $
#$URL: svn://www.crystallography.net/cod/cif/4/31/25/4312599.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_4312599
loop_
_publ_author_name
'Susan E. Latturner'
'Daniel Bilc'
'S. D. Mahanti'
'Mercouri G. Kanatzidis'
_publ_contact_author
; 
     Prof. M. G. Kanatzidis
     Department of Chemistry
     Michigan State University
     East Lansing, MI  48824    
;
_publ_contact_author_email       kanatzid@cem.msu.edu
_publ_contact_author_phone       '(517) 355-9715'
_publ_section_title
;
 RE2MAl6Si4 (RE = Gd, Tb, Dy; M = Au, Pt): Layered Quaternary
 Intermetallics Featuring CaAl2Si2-Type and YNiAl4Ge2-Type Slabs Grown
 from Aluminum Flux
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              7959
_journal_page_last               7966
_journal_paper_doi               10.1021/ic0346432
_journal_volume                  42
_journal_year                    2003
_chemical_formula_sum            'Al6 Dy2 Pt Si4'
_chemical_formula_weight         794.34
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           166
_symmetry_cell_setting           rhombohedral
_symmetry_space_group_name_Hall  '-R 3 2"'
_symmetry_space_group_name_H-M   'R -3 m :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   4.1501(12)
_cell_length_b                   4.1501(12)
_cell_length_c                   50.64(2)
_cell_measurement_temperature    293(2)
_cell_volume                     755.3(4)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0417
_diffrn_reflns_av_sigmaI/netI    0.0180
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       64
_diffrn_reflns_limit_l_min       -60
_diffrn_reflns_number            2547
_diffrn_reflns_theta_full        28.17
_diffrn_reflns_theta_max         28.17
_diffrn_reflns_theta_min         1.21
_exptl_absorpt_coefficient_mu    9.765
_exptl_crystal_density_diffrn    5.239
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             318
_refine_diff_density_max         1.375
_refine_diff_density_min         -1.429
_refine_diff_density_rms         0.288
_refine_ls_extinction_coef       0.00160(14)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.243
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     22
_refine_ls_number_reflns         297
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.243
_refine_ls_R_factor_all          0.0232
_refine_ls_R_factor_gt           0.0212
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[σ²(Fo²)+(0.0284P)²+6.6141P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0530
_refine_ls_wR_factor_ref         0.0535
_reflns_number_gt                283
_reflns_number_total             297
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic0346432si20030609_054510_5.cif
_cod_data_source_block           2sl66a
_cod_original_sg_symbol_H-M      'R -3 m'
_cod_database_code               4312599
loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-y, x-y, z'
'-x+y, -x, z'
'y, x, -z'
'x-y, -y, -z'
'-x, -x+y, -z'
'x+2/3, y+1/3, z+1/3'
'-y+2/3, x-y+1/3, z+1/3'
'-x+y+2/3, -x+1/3, z+1/3'
'y+2/3, x+1/3, -z+1/3'
'x-y+2/3, -y+1/3, -z+1/3'
'-x+2/3, -x+y+1/3, -z+1/3'
'x+1/3, y+2/3, z+2/3'
'-y+1/3, x-y+2/3, z+2/3'
'-x+y+1/3, -x+2/3, z+2/3'
'y+1/3, x+2/3, -z+2/3'
'x-y+1/3, -y+2/3, -z+2/3'
'-x+1/3, -x+y+2/3, -z+2/3'
'-x, -y, -z'
'y, -x+y, -z'
'x-y, x, -z'
'-y, -x, z'
'-x+y, y, z'
'x, x-y, z'
'-x+2/3, -y+1/3, -z+1/3'
'y+2/3, -x+y+1/3, -z+1/3'
'x-y+2/3, x+1/3, -z+1/3'
'-y+2/3, -x+1/3, z+1/3'
'-x+y+2/3, y+1/3, z+1/3'
'x+2/3, x-y+1/3, z+1/3'
'-x+1/3, -y+2/3, -z+2/3'
'y+1/3, -x+y+2/3, -z+2/3'
'x-y+1/3, x+2/3, -z+2/3'
'-y+1/3, -x+2/3, z+2/3'
'-x+y+1/3, y+2/3, z+2/3'
'x+1/3, x-y+2/3, z+2/3'
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_disorder_assembly
_atom_site_disorder_group
Pt1 Pt 0.0000 0.0000 0.0000 0.0024(2) Uani 1 12 d S . .
Dy2 Dy -0.6667 0.6667 0.100458(9) 0.0030(2) Uani 1 6 d S . .
Si1 Si -1.0000 1.0000 0.13494(6) 0.0040(6) Uani 1 6 d S . .
Si2 Si -0.3333 0.3333 0.06748(6) 0.0025(6) Uani 1 6 d S . .
Al1 Al -0.3333 0.3333 0.14818(6) 0.0046(7) Uani 1 6 d S . .
Al2 Al -0.3333 0.3333 0.01516(7) 0.0031(6) Uani 1 6 d S . .
Al3 Al 0.0000 0.0000 0.04990(6) 0.0045(7) Uani 1 6 d S . .
loop_
_atom_type_symbol
_atom_type_description
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
Al Al 0.0645 0.0514 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Si Si 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Dy Dy -0.1892 4.4098 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Pt Pt -1.7033 8.3905 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
Al2 Pt1 Al2 111.12(7) 19 19_455 ?
Al2 Pt1 Al2 180.00(14) 19 . ?
Al2 Pt1 Al2 68.88(7) 19_455 . ?
Al2 Pt1 Al2 111.12(7) 19 19_565 ?
Al2 Pt1 Al2 111.12(7) 19_455 19_565 ?
Al2 Pt1 Al2 68.88(7) . 19_565 ?
Al2 Pt1 Al2 68.88(7) 19 1_655 ?
Al2 Pt1 Al2 180.00(14) 19_455 1_655 ?
Al2 Pt1 Al2 111.12(7) . 1_655 ?
Al2 Pt1 Al2 68.88(7) 19_565 1_655 ?
Al2 Pt1 Al2 68.88(7) 19 1_545 ?
Al2 Pt1 Al2 68.88(7) 19_455 1_545 ?
Al2 Pt1 Al2 111.12(7) . 1_545 ?
Al2 Pt1 Al2 180.00(14) 19_565 1_545 ?
Al2 Pt1 Al2 111.12(7) 1_655 1_545 ?
Al2 Pt1 Al3 107.76(7) 19 . ?
Al2 Pt1 Al3 107.76(7) 19_455 . ?
Al2 Pt1 Al3 72.24(7) . . ?
Al2 Pt1 Al3 107.76(7) 19_565 . ?
Al2 Pt1 Al3 72.24(7) 1_655 . ?
Al2 Pt1 Al3 72.24(7) 1_545 . ?
Al2 Pt1 Al3 72.24(7) 19 19 ?
Al2 Pt1 Al3 72.24(7) 19_455 19 ?
Al2 Pt1 Al3 107.76(7) . 19 ?
Al2 Pt1 Al3 72.24(7) 19_565 19 ?
Al2 Pt1 Al3 107.76(7) 1_655 19 ?
Al2 Pt1 Al3 107.76(7) 1_545 19 ?
Al3 Pt1 Al3 180.0 . 19 ?
Si2 Dy2 Si2 90.55(7) 1_455 1_565 ?
Si2 Dy2 Si2 90.55(7) 1_455 . ?
Si2 Dy2 Si2 90.55(7) 1_565 . ?
Si2 Dy2 Si1 90.30(5) 1_455 . ?
Si2 Dy2 Si1 90.30(5) 1_565 . ?
Si2 Dy2 Si1 178.79(7) . . ?
Si2 Dy2 Si1 178.79(7) 1_455 1_655 ?
Si2 Dy2 Si1 90.30(5) 1_565 1_655 ?
Si2 Dy2 Si1 90.30(5) . 1_655 ?
Si1 Dy2 Si1 88.84(7) . 1_655 ?
Si2 Dy2 Si1 90.30(5) 1_455 1_545 ?
Si2 Dy2 Si1 178.79(7) 1_565 1_545 ?
Si2 Dy2 Si1 90.30(5) . 1_545 ?
Si1 Dy2 Si1 88.84(7) . 1_545 ?
Si1 Dy2 Si1 88.84(7) 1_655 1_545 ?
Si2 Dy2 Al1 134.02(3) 1_455 1_565 ?
Si2 Dy2 Al1 80.12(6) 1_565 1_565 ?
Si2 Dy2 Al1 134.02(3) . 1_565 ?
Si1 Dy2 Al1 45.35(3) . 1_565 ?
Si1 Dy2 Al1 45.35(3) 1_655 1_565 ?
Si1 Dy2 Al1 98.67(7) 1_545 1_565 ?
Si2 Dy2 Al1 80.12(6) 1_455 1_455 ?
Si2 Dy2 Al1 134.02(3) 1_565 1_455 ?
Si2 Dy2 Al1 134.02(3) . 1_455 ?
Si1 Dy2 Al1 45.35(3) . 1_455 ?
Si1 Dy2 Al1 98.67(7) 1_655 1_455 ?
Si1 Dy2 Al1 45.35(3) 1_545 1_455 ?
Al1 Dy2 Al1 75.14(6) 1_565 1_455 ?
Si2 Dy2 Al1 134.02(3) 1_455 . ?
Si2 Dy2 Al1 134.02(3) 1_565 . ?
Si2 Dy2 Al1 80.12(6) . . ?
Si1 Dy2 Al1 98.67(7) . . ?
Si1 Dy2 Al1 45.35(3) 1_655 . ?
Si1 Dy2 Al1 45.35(3) 1_545 . ?
Al1 Dy2 Al1 75.14(6) 1_565 . ?
Al1 Dy2 Al1 75.14(6) 1_455 . ?
Al1 Si1 Al1 113.02(8) 1_465 1_565 ?
Al1 Si1 Al1 113.02(8) 1_465 1_455 ?
Al1 Si1 Al1 113.02(8) 1_565 1_455 ?
Al1 Si1 Al1 74.36(10) 1_465 25_365 ?
Al1 Si1 Al1 74.36(10) 1_565 25_365 ?
Al1 Si1 Al1 74.36(10) 1_455 25_365 ?
Al1 Si1 Dy2 159.56(14) 1_465 . ?
Al1 Si1 Dy2 76.68(6) 1_565 . ?
Al1 Si1 Dy2 76.68(6) 1_455 . ?
Al1 Si1 Dy2 126.08(5) 25_365 . ?
Al1 Si1 Dy2 76.68(6) 1_465 1_455 ?
Al1 Si1 Dy2 159.56(14) 1_565 1_455 ?
Al1 Si1 Dy2 76.68(6) 1_455 1_455 ?
Al1 Si1 Dy2 126.08(5) 25_365 1_455 ?
Dy2 Si1 Dy2 88.84(7) . 1_455 ?
Al1 Si1 Dy2 76.68(6) 1_465 1_565 ?
Al1 Si1 Dy2 76.68(6) 1_565 1_565 ?
Al1 Si1 Dy2 159.56(14) 1_455 1_565 ?
Al1 Si1 Dy2 126.08(5) 25_365 1_565 ?
Dy2 Si1 Dy2 88.84(7) . 1_565 ?
Dy2 Si1 Dy2 88.84(7) 1_455 1_565 ?
Al3 Si2 Al3 108.54(10) . 1_455 ?
Al3 Si2 Al3 108.54(10) . 1_565 ?
Al3 Si2 Al3 108.54(10) 1_455 1_565 ?
Al3 Si2 Al2 69.62(10) . . ?
Al3 Si2 Al2 69.62(10) 1_455 . ?
Al3 Si2 Al2 69.62(10) 1_565 . ?
Al3 Si2 Dy2 79.32(5) . 1_655 ?
Al3 Si2 Dy2 165.51(13) 1_455 1_655 ?
Al3 Si2 Dy2 79.32(5) 1_565 1_655 ?
Al2 Si2 Dy2 124.88(5) . 1_655 ?
Al3 Si2 Dy2 79.32(5) . 1_545 ?
Al3 Si2 Dy2 79.32(5) 1_455 1_545 ?
Al3 Si2 Dy2 165.51(13) 1_565 1_545 ?
Al2 Si2 Dy2 124.88(5) . 1_545 ?
Dy2 Si2 Dy2 90.55(7) 1_655 1_545 ?
Al3 Si2 Dy2 165.51(13) . . ?
Al3 Si2 Dy2 79.32(5) 1_455 . ?
Al3 Si2 Dy2 79.32(5) 1_565 . ?
Al2 Si2 Dy2 124.88(5) . . ?
Dy2 Si2 Dy2 90.55(7) 1_655 . ?
Dy2 Si2 Dy2 90.55(7) 1_545 . ?
Si1 Al1 Si1 113.02(8) 1_645 1_545 ?
Si1 Al1 Si1 113.02(8) 1_645 1_655 ?
Si1 Al1 Si1 113.02(8) 1_545 1_655 ?
Si1 Al1 Si1 105.64(10) 1_645 25_365 ?
Si1 Al1 Si1 105.64(10) 1_545 25_365 ?
Si1 Al1 Si1 105.64(10) 1_655 25_365 ?
Si1 Al1 Dy2 57.97(6) 1_645 1_545 ?
Si1 Al1 Dy2 57.97(6) 1_545 1_545 ?
Si1 Al1 Dy2 119.11(13) 1_655 1_545 ?
Si1 Al1 Dy2 135.25(4) 25_365 1_545 ?
Si1 Al1 Dy2 57.97(6) 1_645 1_655 ?
Si1 Al1 Dy2 119.11(13) 1_545 1_655 ?
Si1 Al1 Dy2 57.97(6) 1_655 1_655 ?
Si1 Al1 Dy2 135.25(4) 25_365 1_655 ?
Dy2 Al1 Dy2 75.14(6) 1_545 1_655 ?
Si1 Al1 Dy2 119.11(13) 1_645 . ?
Si1 Al1 Dy2 57.97(6) 1_545 . ?
Si1 Al1 Dy2 57.97(6) 1_655 . ?
Si1 Al1 Dy2 135.25(4) 25_365 . ?
Dy2 Al1 Dy2 75.14(6) 1_545 . ?
Dy2 Al1 Dy2 75.14(6) 1_655 . ?
Pt1 Al2 Pt1 111.12(7) . 1_455 ?
Pt1 Al2 Pt1 111.12(7) . 1_565 ?
Pt1 Al2 Pt1 111.12(7) 1_455 1_565 ?
Pt1 Al2 Si2 107.76(7) . . ?
Pt1 Al2 Si2 107.76(7) 1_455 . ?
Pt1 Al2 Si2 107.76(7) 1_565 . ?
Pt1 Al2 Al2 55.56(3) . 19_455 ?
Pt1 Al2 Al2 55.56(3) 1_455 19_455 ?
Pt1 Al2 Al2 129.59(18) 1_565 19_455 ?
Si2 Al2 Al2 122.65(11) . 19_455 ?
Pt1 Al2 Al2 55.56(3) . 19_565 ?
Pt1 Al2 Al2 129.59(18) 1_455 19_565 ?
Pt1 Al2 Al2 55.56(3) 1_565 19_565 ?
Si2 Al2 Al2 122.65(11) . 19_565 ?
Al2 Al2 Al2 93.64(15) 19_455 19_565 ?
Pt1 Al2 Al2 129.59(18) . 19_465 ?
Pt1 Al2 Al2 55.56(3) 1_455 19_465 ?
Pt1 Al2 Al2 55.56(3) 1_565 19_465 ?
Si2 Al2 Al2 122.65(11) . 19_465 ?
Al2 Al2 Al2 93.64(15) 19_455 19_465 ?
Al2 Al2 Al2 93.64(15) 19_565 19_465 ?
Pt1 Al2 Al3 124.36(4) . 1_565 ?
Pt1 Al2 Al3 124.36(4) 1_455 1_565 ?
Pt1 Al2 Al3 54.05(6) 1_565 1_565 ?
Si2 Al2 Al3 53.71(7) . 1_565 ?
Al2 Al2 Al3 176.36(17) 19_455 1_565 ?
Al2 Al2 Al3 88.85(6) 19_565 1_565 ?
Al2 Al2 Al3 88.85(6) 19_465 1_565 ?
Pt1 Al2 Al3 54.05(6) . . ?
Pt1 Al2 Al3 124.36(4) 1_455 . ?
Pt1 Al2 Al3 124.36(4) 1_565 . ?
Si2 Al2 Al3 53.71(7) . . ?
Al2 Al2 Al3 88.85(6) 19_455 . ?
Al2 Al2 Al3 88.85(6) 19_565 . ?
Al2 Al2 Al3 176.36(17) 19_465 . ?
Al3 Al2 Al3 88.54(11) 1_565 . ?
Pt1 Al2 Al3 124.36(4) . 1_455 ?
Pt1 Al2 Al3 54.05(6) 1_455 1_455 ?
Pt1 Al2 Al3 124.36(4) 1_565 1_455 ?
Si2 Al2 Al3 53.71(7) . 1_455 ?
Al2 Al2 Al3 88.85(6) 19_455 1_455 ?
Al2 Al2 Al3 176.36(17) 19_565 1_455 ?
Al2 Al2 Al3 88.85(6) 19_465 1_455 ?
Al3 Al2 Al3 88.54(11) 1_565 1_455 ?
Al3 Al2 Al3 88.54(11) . 1_455 ?
Pt1 Al3 Si2 110.38(10) . . ?
Pt1 Al3 Si2 110.38(10) . 1_655 ?
Si2 Al3 Si2 108.54(10) . 1_655 ?
Pt1 Al3 Si2 110.38(10) . 1_545 ?
Si2 Al3 Si2 108.54(10) . 1_545 ?
Si2 Al3 Si2 108.54(10) 1_655 1_545 ?
Pt1 Al3 Al2 53.71(7) . 1_545 ?
Si2 Al3 Al2 125.73(5) . 1_545 ?
Si2 Al3 Al2 125.73(5) 1_655 1_545 ?
Si2 Al3 Al2 56.67(8) 1_545 1_545 ?
Pt1 Al3 Al2 53.71(7) . . ?
Si2 Al3 Al2 56.67(8) . . ?
Si2 Al3 Al2 125.73(5) 1_655 . ?
Si2 Al3 Al2 125.73(5) 1_545 . ?
Al2 Al3 Al2 88.54(11) 1_545 . ?
Pt1 Al3 Al2 53.71(7) . 1_655 ?
Si2 Al3 Al2 125.73(5) . 1_655 ?
Si2 Al3 Al2 56.67(8) 1_655 1_655 ?
Si2 Al3 Al2 125.73(5) 1_545 1_655 ?
Al2 Al3 Al2 88.54(11) 1_545 1_655 ?
Al2 Al3 Al2 88.54(11) . 1_655 ?
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
Pt1 Al2 2.5160(12) 19 ?
Pt1 Al2 2.5160(12) 19_455 ?
Pt1 Al2 2.5160(12) . ?
Pt1 Al2 2.5160(12) 19_565 ?
Pt1 Al2 2.5160(12) 1_655 ?
Pt1 Al2 2.5160(12) 1_545 ?
Pt1 Al3 2.527(3) . ?
Pt1 Al3 2.527(3) 19 ?
Dy2 Si2 2.9206(19) 1_455 ?
Dy2 Si2 2.9206(19) 1_565 ?
Dy2 Si2 2.9206(19) . ?
Dy2 Si1 2.965(2) . ?
Dy2 Si1 2.965(2) 1_655 ?
Dy2 Si1 2.965(2) 1_545 ?
Dy2 Al1 3.403(2) 1_565 ?
Dy2 Al1 3.403(2) 1_455 ?
Dy2 Al1 3.403(2) . ?
Si1 Al1 2.4882(14) 1_465 ?
Si1 Al1 2.4882(14) 1_565 ?
Si1 Al1 2.4882(14) 1_455 ?
Si1 Al1 2.543(5) 25_365 ?
Si1 Dy2 2.965(2) 1_455 ?
Si1 Dy2 2.965(2) 1_565 ?
Si2 Al3 2.5561(17) . ?
Si2 Al3 2.5561(17) 1_455 ?
Si2 Al3 2.5561(17) 1_565 ?
Si2 Al2 2.650(4) . ?
Si2 Dy2 2.9206(19) 1_655 ?
Si2 Dy2 2.9206(19) 1_545 ?
Al1 Si1 2.4882(14) 1_645 ?
Al1 Si1 2.4882(14) 1_545 ?
Al1 Si1 2.4882(14) 1_655 ?
Al1 Si1 2.543(5) 25_365 ?
Al1 Dy2 3.403(2) 1_545 ?
Al1 Dy2 3.403(2) 1_655 ?
Al2 Pt1 2.5160(12) 1_455 ?
Al2 Pt1 2.5160(12) 1_565 ?
Al2 Al2 2.846(4) 19_455 ?
Al2 Al2 2.846(4) 19_565 ?
Al2 Al2 2.846(4) 19_465 ?
Al2 Al3 2.973(3) 1_565 ?
Al2 Al3 2.973(3) . ?
Al2 Al3 2.973(3) 1_455 ?
Al3 Si2 2.5561(17) 1_655 ?
Al3 Si2 2.5561(17) 1_545 ?
Al3 Al2 2.973(3) 1_545 ?
Al3 Al2 2.973(3) 1_655 ?
