#------------------------------------------------------------------------------
#$Date: 2016-02-21 01:03:34 +0100 (dom 21 de feb de 2016) $
#$Revision: 176798 $
#$URL: svn://www.crystallography.net/cod/cif/2/23/72/2237244.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_2237244
loop_
_publ_author_name
'Bell, Anthony M. T.'
'Henderson, C. Michael B.'
_publ_section_title
;
 Sr--fresnoite determined from synchrotron X-ray powder diffraction data
;
_journal_coeditor_code           WM2699
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              i1
_journal_paper_doi               10.1107/S1600536812048921
_journal_volume                  69
_journal_year                    2013
_chemical_formula_iupac          'Sr2 Ti Si2 O8'
_chemical_formula_structural     'Sr2 Ti Si2 O8'
_chemical_formula_sum            'O8 Si2 Sr2 Ti'
_chemical_formula_weight         407.31
_chemical_name_common            'Strontium fresnoite'
_chemical_name_systematic
;
Distrontium oxidotitanium disilicate
;
_space_group_IT_number           100
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4 -2ab'
_symmetry_space_group_name_H-M   'P 4 b m'
_cell_angle_alpha                90.00000
_cell_angle_beta                 90.00000
_cell_angle_gamma                90.00000
_cell_formula_units_Z            2
_cell_length_a                   8.3200(3)
_cell_length_b                   8.3200(3)
_cell_length_c                   5.0239(2)
_cell_measurement_temperature    293
_cell_volume                     347.77(2)
_computing_cell_refinement       'local software'
_computing_data_collection       'local software'
_computing_data_reduction        'local software'
_computing_molecular_graphics    'VESTA (Momma & Izumi, 2008)'
_computing_publication_material  'publCIF (Westrip, 2010)'
_computing_structure_refinement  'FULLPROF (Rodriguez-Carvajal, 2001)'
_computing_structure_solution    'coordinates taken from a related compound'
_diffrn_ambient_temperature      293
_diffrn_measurement_device_type  'In-house design'
_diffrn_radiation_monochromator  'Laue DCM diamond(111) & Si(111)'
_diffrn_radiation_type           Synchrotron
_diffrn_radiation_wavelength     0.207549
_exptl_absorpt_coefficient_mu    0.43
_exptl_crystal_density_diffrn    3.8896(2)
_exptl_crystal_density_method    'not measured'
_pd_block_diffractogram_id       srfrespd
_pd_char_colour                  white
_pd_char_particle_morphology     powder
_pd_instr_location
;
P02.1 Powder Diffraction beamline, PETRA-III synchrotron, Hamburg.
;
_pd_meas_2theta_range_inc        0.008081
_pd_meas_2theta_range_max        11.91532
_pd_meas_2theta_range_min        0.05249
_pd_meas_number_of_points        1476
_pd_meas_scan_method             cont
_pd_prep_pressure                100
_pd_prep_temperature             1323
_pd_proc_2theta_range_inc        0.008081
_pd_proc_2theta_range_max        11.9153
_pd_proc_2theta_range_min        0.0525
_pd_proc_info_excluded_regions   '0-1 and 11.7-12.0 degrees 2\q'
_pd_proc_ls_profile_function     'T-C-H Pseudo-Voigt function'
_pd_proc_ls_prof_R_factor        0.052
_pd_proc_ls_prof_wR_expected     0.031
_pd_proc_ls_prof_wR_factor       0.073
_pd_proc_wavelength              0.207549
_pd_spec_mounting                capillary
_pd_spec_mount_mode              transmission
_pd_spec_shape                   cylinder
_pd_spec_size_axial              20
_pd_spec_size_equat              0.7
_pd_spec_size_thick              0.7
_refine_ls_goodness_of_fit_all   5.5739
_refine_ls_number_parameters     71
_refine_ls_number_reflns         125
_refine_ls_number_restraints     5
_cod_data_source_file            wm2699.cif
_cod_data_source_block           I
_cod_database_code               2237244
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
-y,x,z
-x,-y,z
y,-x,z
-x+1/2,y+1/2,z
y+1/2,x+1/2,z
x+1/2,-y+1/2,z
-y+1/2,-x+1/2,z
loop_
_atom_site_type_symbol
_atom_site_label
_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
Sr Sr1 0.3282(2) 0.8282(2) 0.017(2) 0.0070(8) Uiso 1.00000
Ti Ti1 0.00000 0.00000 0.558(3) 0.007(2) Uiso 1.00000
Si Si1 0.1305(6) 0.6305(6) 0.535(3) 0.019(2) Uiso 1.00000
O O1 0.00000 0.50000 0.651(5) 0.017(3) Uiso 1.00000
O O2 0.1292(15) 0.6292(15) 0.191(3) 0.017(3) Uiso 1.00000
O O3 0.2985(12) 0.5984(15) 0.678(3) 0.017(3) Uiso 1.00000
O O4 0.00000 0.00000 0.209(3) 0.017(3) Uiso 1.00000
loop_
_atom_type_symbol
_atom_type_scat_Cromer_Mann_a1
_atom_type_scat_Cromer_Mann_a2
_atom_type_scat_Cromer_Mann_a3
_atom_type_scat_Cromer_Mann_a4
_atom_type_scat_Cromer_Mann_b1
_atom_type_scat_Cromer_Mann_b2
_atom_type_scat_Cromer_Mann_b3
_atom_type_scat_Cromer_Mann_b4
_atom_type_scat_Cromer_Mann_c
_atom_type_scat_dispersion_real
_atom_type_scat_dispersion_imag
_atom_type_scat_source
Sr 17.56630 9.81840 5.42200 2.66940 1.55640 14.09880 0.16640 132.37601 2.50640
-0.23000 2.20300 International_Tables_Vol.C(1991)_Tables_6.1.1.4_and_6.1.1.5
Ti 9.75950 7.35580 1.69910 1.90210 7.85080 0.50000 35.63380 116.10500 1.28070
0.17500 0.28300 International_Tables_Vol.C(1991)_Tables_6.1.1.4_and_6.1.1.5
Si 6.29150 3.03530 1.98910 1.54100 2.43860 32.33370 0.67850 81.69370 1.14070
0.04200 0.04300 International_Tables_Vol.C(1991)_Tables_6.1.1.4_and_6.1.1.5
O 3.0485 2.2868 1.5463 0.8670 13.2771 5.7011 0.3239 32.9089 0.2508 0.0030
0.0040 International_Tables_Vol.C(1991)_Tables_6.1.1.4_and_6.1.1.5
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_2
_geom_angle_site_symmetry_3
_geom_angle
O3 Ti1 O3 5_555 1_565 8_565 84.6(9)
O3 Ti1 O3 5_555 1_565 7_465 144.2(10)
O3 Ti1 O3 7_465 1_565 8_565 84.6(8)
O3 Ti1 O4 5_555 1_565 1_565 107.9(12)
O3 Ti1 O3 7_465 1_565 6_455 84.6(8)
O3 Ti1 O3 8_565 1_565 6_455 144.2(11)
O3 Ti1 O4 8_565 1_565 1_565 107.9(12)
O3 Ti1 O3 6_455 1_565 5_555 84.6(9)
O3 Ti1 O4 6_455 1_565 1_565 107.9(12)
O3 Ti1 O4 7_465 1_565 1_565 107.9(12)
O1 Si1 O2 1_555 1_555 1_555 110.3(16)
O1 Si1 O3 1_555 1_555 6_455 108.0(9)
O1 Si1 O3 1_555 1_555 1_555 108.0(10)
O2 Si1 O3 1_555 1_555 1_555 117.1(15)
O2 Si1 O3 1_555 1_555 6_455 117.1(15)
O3 Si1 O3 6_455 1_555 1_555 95.2(11)
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_site_symmetry_2
_geom_bond_distance
Sr1 O1 2_664 2.733(18)
Sr1 O2 . 2.499(13)
Sr1 O2 2_665 2.676(13)
Sr1 O2 4_565 2.676(13)
Sr1 O3 1_554 2.572(15)
Sr1 O3 6_454 2.572(14)
Ti1 O3 5_545 1.961(12)
Ti1 O3 6_445 1.961(13)
Ti1 O3 7_455 1.961(12)
Ti1 O3 8_555 1.961(13)
Ti1 O4 . 1.75(2)
Si1 O1 . 1.642(11)
Si1 O2 . 1.73(2)
Si1 O3 . 1.594(14)
Si1 O3 6_455 1.594(15)
