On the Crystal Chemistry of RE2Si2O7: Revisited Structures, Group–Subgroup Relationship, and Insights of Ce3±Activated Radioluminescence
Chen, Pengyun; Zhou, Yuqiao; He, Jin; Jiang, Wei; Li, Junhao; Ni, Haiyong; Zhang, Qiuhong; Lin, Litian; Chemistry of Materials 35 (2023) 2635–2646; doi:10.1021/acs.chemmater.3c00245

data_4004091
_publ_section_title
;
 On the Crystal Chemistry of RE2Si2O7: Revisited Structures,
 Group--Subgroup Relationship, and Insights of Ce3+-Activated
 Radioluminescence
;
_journal_issue                   6
_journal_name_full               'Chemistry of Materials'
_journal_page_first              2635
_journal_page_last               2646
_journal_paper_doi               10.1021/acs.chemmater.3c00245
_journal_volume                  35
_journal_year                    2023
_chemical_formula_sum            'Eu2 O7 Si2'
_chemical_formula_weight         472.10
_space_group_crystal_system      orthorhombic
_space_group_IT_number           62
_space_group_name_Hall           '-P 2ac 2n'
_space_group_name_H-M_alt        'P n m a'
_atom_sites_solution_hydrogens   .
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   13.9144(4)
_cell_length_b                   8.3502(3)
_cell_length_c                   5.0557(2)
_cell_measurement_reflns_used    120
_cell_measurement_temperature    294(2)
_cell_measurement_theta_max      20
_cell_measurement_theta_min      5
_cell_volume                     587.41(4)
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      294(2)
_diffrn_measured_fraction_theta_full 0.975
_diffrn_measured_fraction_theta_max 0.976
_diffrn_measurement_device_type  'Bruker D8 Quest'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0231
_diffrn_reflns_av_unetI/netI     0.0188
_diffrn_reflns_Laue_measured_fraction_full 0.975
_diffrn_reflns_Laue_measured_fraction_max 0.976
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -5
_diffrn_reflns_number            2987
_diffrn_reflns_point_group_measured_fraction_full 0.975
_diffrn_reflns_point_group_measured_fraction_max 0.976
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.348
_diffrn_reflns_theta_min         2.928
_exptl_absorpt_coefficient_mu    21.550
_exptl_absorpt_correction_T_max  0.2
_exptl_absorpt_correction_T_min  0.1
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    5.338
_exptl_crystal_description       prism
_exptl_crystal_F_000             840
_exptl_crystal_size_max          0.142
_exptl_crystal_size_mid          0.105
_exptl_crystal_size_min          0.070
_refine_diff_density_max         0.540
_refine_diff_density_min         -0.542
_refine_diff_density_rms         0.150
_refine_ls_extinction_coef       0.0199(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2018/3 (Sheldrick 2018)'
_refine_ls_goodness_of_fit_ref   1.246
_refine_ls_hydrogen_treatment    undef
_refine_ls_matrix_type           full
_refine_ls_number_parameters     59
_refine_ls_number_reflns         558
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.246
_refine_ls_R_factor_all          0.0160
_refine_ls_R_factor_gt           0.0151
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0051P)^2^+2.4069P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0336
_refine_ls_wR_factor_ref         0.0341
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                536
_reflns_number_total             558
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            E-1-Eu2Si2O7.cif
_cod_data_source_block           Eu2Si2O7
_cod_database_code               4004091
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.150
_shelx_estimated_absorpt_t_max   0.314
_shelx_res_checksum              26307
_shelx_hkl_checksum              11337