Polymorphism of BaTeMo2O9: A New Polar Polymorph and the Phase Transformation
Zhang, Junjie; Zhang, Zhonghan; Zhang, Weiguo; Zheng, Qingxin; Sun, Youxuan; Zhang, Chengqian; Tao, Xutang; Chemistry of Materials 23 (2011) 3752–; doi:10.1021/cm2015143

data_4000792
_publ_section_title
;
 Polymorphism of BaTeMo2O9: A New Polar Polymorph and the Phase
 Transformation
;
_journal_issue                   16
_journal_name_full               'Chemistry of Materials'
_journal_page_first              3752
_journal_paper_doi               10.1021/cm2015143
_journal_volume                  23
_journal_year                    2011
_chemical_formula_moiety         ' Mo4 O18 Te2, 2(Ba)'
_chemical_formula_sum            'Ba Mo2 O9 Te'
_chemical_formula_weight         600.82
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_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                90.00
_cell_formula_units_Z            8
_cell_length_a                   14.8683(2)
_cell_length_b                   5.6636(1)
_cell_length_c                   17.6849(3)
_cell_measurement_reflns_used    8329
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      36.79
_cell_measurement_theta_min      3.58
_cell_volume                     1489.21(4)
_computing_cell_refinement       'APEX2 Software Suite (Bruker,2005)'
_computing_data_collection       'APEX2 Software Suite (Bruker,2005)'
_computing_data_reduction        'APEX2 Software Suite (Bruker,2005)'
_computing_molecular_graphics    'SHELXTL (Bruker, 1997)'
_computing_publication_material  'WINGX (Farrugia,1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare,1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.944
_diffrn_measurement_device_type
'Bruker APEX2 CCD area-detector diffractometer'
_diffrn_measurement_method       '\f and \w scans'
_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  0.0211
_diffrn_reflns_av_sigmaI/netI    0.0280
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            14719
_diffrn_reflns_theta_full        32.50
_diffrn_reflns_theta_max         37.15
_diffrn_reflns_theta_min         2.30
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    12.411
_exptl_absorpt_correction_T_max  0.3422
_exptl_absorpt_correction_T_min  0.2754
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'APEX2 Software Suite (Bruker,2005)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    5.360
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2112
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.11
_refine_diff_density_max         1.298
_refine_diff_density_min         -0.948
_refine_diff_density_rms         0.212
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.064(16)
_refine_ls_extinction_coef       0.00233(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.107
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         5906
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.107
_refine_ls_R_factor_all          0.0220
_refine_ls_R_factor_gt           0.0205
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0083P)^2^+1.3711P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0383
_refine_ls_wR_factor_ref         0.0387
_reflns_number_gt                5691
_reflns_number_total             5906
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            cm2015143_si_002.cif
_cod_data_source_block           zhangjj01
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_Hall     'P 2c -2ac '
_cod_original_sg_symbol_H-M      'Pca2(1) '
_cod_database_code               4000792