CIF required items for single-crystal reports

This page lists the data items that are required for a single-crystal study. For a list of items to include in a powder diffraction study, please click here.

Detailed descriptions of these data items are given in the core CIF dictionary [see also Hall et al. (1991). Acta Cryst. A47, 655-685].

New names listed below are flagged with (new) and in some cases are followed by old names [in regular type and flagged with (old)] which are accepted but will be discontinued in the future. Authors may also include other data items in the CIF (see the two _publ_manuscript_incl_extra_ entries towards the end of the list) provided their data names are also listed in the _publ_contact_letter text.

Text items
_publ_contact_author_name Contact author's name
_publ_contact_author_address Contact author's address
_publ_contact_author Contact author's name and address (old)
_publ_contact_author_email E-mail address to be published
_publ_contact_author_fax For editorial communications
_publ_contact_author_phone For editorial communications
_publ_contact_letter Letter of submission, with date
_publ_requested_journal 'Acta Crystallographica Section C'
_publ_section_title Title of paper
_publ_section_title_footnote Footnote to title of paper
_publ_author_name List of author(s) name(s)
_publ_author_footnote Footnote(s) to author(s) name(s)
_publ_author_address Author(s) address(es)
_publ_section_synopsis Synopsis for compounds that cannot be shown as a chemical diagram. Not required for Acta Cryst. Section E.
_publ_section_abstract Abstract of paper in English
_publ_section_comment
or
loop_
_publ_body_element
_publ_body_title
_publ_body_contents
(author defined sections; use of
http://publcif.iucr.org recommended)
Discussion of study
_publ_section_acknowledgements Acknowledgements
_publ_section_references References
_publ_section_figure_captions Legends to figures
   
Experimental data (machine and author generated)  
_publ_section_exptl_prep Compound preparation details
_publ_section_exptl_refinement Special details of the refinement
_chemical_formula_sum Chemical formula as sum of elements
_chemical_formula_moiety Chemical formula in moieties
_chemical_formula_weight Chemical formula mass (Da)
_chemical_melting_point Melting point (K)
_space_group_crystal_system Code for cell setting
_space_group_name_H-M_alt
_symmetry_space_group_name_H-M (old)
Space-group symbol, including unique axis
_space_group_symop_operation_xyz
_symmetry_equiv_pos_as_xyz (old)
Equivalent positions in order used by _geom_
_space_group_name_Hall
_symmetry_space_group_name_Hall (old)
The Hall space group symbol
_space_group_IT_number (optional)
_symmetry_Int_Tables_number (old)
The space group number as used in International Tables, Volume A
_cell_length_a
_cell_length_b
_cell_length_c
Unit-cell lengths (Å)
_cell_angle_alpha
_cell_angle_beta
_cell_angle_gamma
Unit-cell angles (°)
_cell_volume Unit-cell volume (Å3)
_cell_formula_units_Z Number of formulae per unit cell
_exptl_crystal_density_diffrn Density calculated from unit cell and contents (Mg m-3)
_exptl_crystal_density_meas (optional) Density measured experimentally (Mg m-3)
_exptl_crystal_density_method (optional; only use if previous item present) Method used to measure density experimentally
_diffrn_radiation_type Radiation type (e.g. neutron or `Mo Ktex2html_wrap_inline30')
_diffrn_radiation_wavelength Radiation wavelength (Å)
_cell_measurement_reflns_used Number of reflections used to measure unit cell
_cell_measurement_theta_min Minimum tex2html_wrap_inline68 of reflections used to measure unit cell (°)
_cell_measurement_theta_max Maximum tex2html_wrap_inline68 of reflections used to measure unit cell (°)
_cell_measurement_temperature Measurement temperature (K)
_exptl_absorpt_coefficient_mu Linear absorption coefficient (mm-1)
_exptl_crystal_description Crystal habit description
_exptl_crystal_size_max Maximum dimension of crystal (mm)
_exptl_crystal_size_mid Medial dimension of crystal (mm)
_exptl_crystal_size_min Minimum dimension of crystal (mm)
_exptl_crystal_size_rad
(alternative to the three preceding items)
Radius of spherical or cylindrical crystal (mm)
_exptl_crystal_colour Crystal colour
_diffrn_measurement_device_type Diffractometer make and type
_diffrn_measurement_device Diffractometer make and type (old)
_diffrn_measurement_method Mode of intensity measurement and scan
_diffrn_detector_area_resol_mean Resolution of area detector (pixels mm-1)
_exptl_absorpt_correction_type Code for absorption correction
_exptl_absorpt_process_details Literature reference for absorption correction [e.g. '(North et al., 1968)']
_exptl_absorpt_correction_T_min Minimum transmission factor from the absorption correction applied (e.g. not including scaling)
_exptl_absorpt_correction_T_max Maximum transmission factor from the absorption correction applied (e.g. not including scaling)
_diffrn_reflns_number Total number of reflections measured excluding systematic absences
_reflns_number_total Number of symmetry-independent reflections excluding systematic absences
_reflns_number_gt Number of reflections > tex2html_wrap_inline74 threshold
_reflns_threshold_expression tex2html_wrap_inline74 expression for F, F2 or I threshold
_diffrn_reflns_theta_max Maximum tex2html_wrap_inline68 of measured reflections (°)
_diffrn_reflns_theta_min Minimum tex2html_wrap_inline68 of measured reflections (°)
_diffrn_reflns_theta_full tex2html_wrap_inline68 to which available reflections are close to 100% complete (°)
_diffrn_measured_fraction_theta_max Fraction of unique reflections measured to tex2html_wrap_inline68max
_diffrn_measured_fraction_theta_full Fraction of unique reflections measured to tex2html_wrap_inline68full
_diffrn_reflns_av_R_equivalents R factor for symmetry-equivalent intensities
_diffrn_reflns_limit_h_min
_diffrn_reflns_limit_h_max
Minimum/maximum h index of measured data
_diffrn_reflns_limit_k_min
_diffrn_reflns_limit_k_max
Minimum/maximum k index of measured data
_diffrn_reflns_limit_l_min
_diffrn_reflns_limit_l_max
Minimum/maximum l index of measured data
_diffrn_reflns_Laue_measured_fraction_max (SHELXL2012 or later) Fraction of Laue unique reflections (symmetry-independent in the Laue group) measured out to tex2html_wrap_inline68max
_diffrn_reflns_Laue_measured_fraction_full (SHELXL2012 or later) Fraction of Laue unique reflections (symmetry-independent in the Laue group) measured out to tex2html_wrap_inline68full
_diffrn_reflns_point_group_measured_fraction_max (SHELXL2012 or later) Fraction of crystal point-group unique reflections (i.e. symmetry-independent in the crystal point group) measured out to tex2html_wrap_inline68max
_diffrn_reflns_point_group_measured_fraction_full (SHELXL2012 or later) Fraction of crystal point-group unique reflections (i.e. symmetry-independent in the crystal point group) measured out to tex2html_wrap_inline68full
_reflns_Friedel_coverage (SHELXL2012 or later) The proportion of Friedel-related reflections present in the number of reported unique reflections
_reflns_Friedel_fraction_max (SHELXL2012 or later) The number of unique Friedel pairs measured divided by the number that would be possible theoretically, ignoring centric projections and systematic absences out to tex2html_wrap_inline68max
_reflns_Friedel_fraction_full (SHELXL2012 or later) The number of unique Friedel pairs measured divided by the number that would be possible theoretically, ignoring centric projections and systematic absences out to tex2html_wrap_inline68full
_diffrn_standards_number
(optional - only needed if a point detector is used)
Number of standards used in measurement (enter zero if none)
_diffrn_standards_interval_count
(optional - only needed if a point detector is used) _diffrn_standards_interval_time (alternate)
Number of measurements between standards
Time (min) between standards
_diffrn_standards_decay_%
(optional - only needed if a point detector is used)
Percentage decrease in standards intensity
_refine_ls_structure_factor_coef Code for F, F2 or I used in least-squares refinement
_refine_ls_R_factor_gt R factor of F for reflections > threshold
_refine_ls_wR_factor_ref R factor of coefficient for refinement reflections
_refine_ls_goodness_of_fit_ref Goodness of fit S for refinement reflections
_refine_ls_number_reflns Number of reflections used in refinement
_refine_ls_number_parameters Number of parameters refined
_refine_ls_number_restraints Number of restraints applied during refinement
_refine_ls_weighting_scheme Code for weight type
_refine_ls_weighting_details Weighting expression
_refine_ls_hydrogen_treatment Code for H-atom treatment
_refine_ls_shift/su_max Maximum shift/s.u. ratio after final refinement cycle
_refine_ls_shift/esd_max Maximum shift/e.s.d. ratio after final refinement cycle (old)
_refine_diff_density_max
_refine_diff_density_min
Maximum/minimum values of final difference map (e Å-3)
_refine_ls_extinction_method Description of extinction methods applied
_refine_ls_extinction_coef Extinction coefficient applied in corrections
_refine_ls_abs_structure_details Absolute structure method and Friedel-pair number
_refine_ls_abs_structure_Flack Measure of absolute structure. May be used to report the estimated Flack x parameter, the Hooft y parameter, the Parsons quotient z parameter or the refined Flack parameter (using TWIN/BASF)
_chemical_absolute_configuration Code for specifying how the absolute structure was assigned
_computing_data_collection Reference to data-collection software
_comput ing_cell_refinement Reference to cell-refinement software
_computing_data_reduction Reference to data-reduction software
_computing_structure_solution Reference to structure-solution software
_computing_structure_refinement Reference to structure-refinement software
_computing_molecular_graphics Reference to visualization software
_computing_publication_material Reference to publication preparation software
   
loop_  
_atom_site_label Unique label identifying the atom site
_atom_site_type_symbol Atom type symbol (usually element symbol)
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Fractional coordinates of atom site
_atom_site_U_iso_or_equiv Isotropic atomic displacement parameter, or equivalent from anisotropic atomic displacement parameters
_atom_site_adp_type Atomic displacement parameter type
_atom_site_occupancy Occupancy fraction for site (default is 1.0). Normally, the occupancy is 1.0, even on a special position. Occupancy is < 1 usually only for disorder.
_atom_site_site_symmetry_order This is the number of times application of the crystallographic symmetry operators of the space group to the coordinates given for this site generates the same set of coordinates.
_atom_site_site_symmetry_multiplicity (alternative to _atom_site_site_symmetry_order) The number of different sites that are generated by the application of the space-group symmetry to the coordinates given for this site. It is equal to the multiplicity given for this Wyckoff site in International Tables for Crystallography Volume A (2002)
_atom_site_site_symmetry_multiplicity (old) Replaced by atom_site_site_site_symmetry_multiplicity given above because of inconsistent usage
_atom_site_calc_flag Code to signal whether the site coordinates have been determined from the intensities or calculated from the geometry of surrounding sites
_atom_site_refinement_flags_posn Flags for specifying restraints or constraints applied to the positional coordinates of the atom
_atom_site_refinement_flags_adp Flags for specifying restraints or constraints applied to the atomic displacement parameters of the atom
atom_site_refinement_flags_occupancy Flags for specifying restraints or constraints applied to the occupancy of the atom
_atom_site_refinement_flags
(alternative to the three preceding items)
A concatenated series of single-letter flags for specifying restraints or constraints applied to the atom
_atom_site_disorder_assembly Code that identifies functional group suffering disorder
_atom_site_disorder_group Code that identifies disorder group
   
loop_  
_atom_type_symbol Atom type symbol (usually element symbol)
_atom_type_description Description of atom type
_atom_type_scat_source Reference to scattering factors applied
_atom_type_scat_dispersion_real Real anomalous-dispersion value applied
_atom_type_scat_dispersion_imag Imaginary anomalous-dispersion value applied
   
loop_  
_atom_site_aniso_label Unique label identifying the atom site
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Elements of anisotropic atomic displacement parameter tensor
   
loop_  
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
Labels identifying the atom sites 1 and 2
_geom_bond_site_symmetry_1
_geom_bond_site_symmetry_2
Symmetry codes (e.g. 2_554) for atom sites 1 and 2
_geom_bond_distance Distance between atom sites 1 and 2 (Å)
_geom_bond_publ_flag Flag for print request (yes or no)
   
loop_  
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
Labels identifying the atom sites 1, 2 and 3
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_2
_geom_angle_site_symmetry_3
Symmetry codes for atom sites 1, 2 and 3
_geom_angle Angle between atom sites 1, 2 and 3 (°)
_geom_angle_publ_flag Flag for print request (yes or no)
   
loop_  
_geom_torsion_atom_site_label_1
_geom_torsion_atom_site_label_2
_geom_torsion_atom_site_label_3
_geom_torsion_atom_site_label_4
Labels identifying the atom sites 1, 2, 3 and 4
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
Symmetry codes for atom sites 1, 2, 3 and 4
_geom_torsion Torsion angle between atom sites 1, 2, 3 and 4 (°)
_geom_torsion_publ_flag Flag for print request (yes or no)
   
loop_  
_geom_hbond_atom_site_label_D Donor-atom label in hydrogen bond
_geom_hbond_atom_site_label_H H-atom label in hydrogen bond
_geom_hbond_atom_site_label_A Acceptor-atom label in hydrogen bond
_geom_hbond_site_symmetry_D Symmetry code for donor site
_geom_hbond_site_symmetry_H Symmetry code for H-atom site
_geom_hbond_site_symmetry_A Symmetry code for acceptor site
_geom_hbond_distance_DH Donor atom-to-H-atom distance (Å)
_geom_hbond_distance_HA H-atom-to-acceptor atom distance (Å)
_geom_hbond_distance_DA Donor atom-to-acceptor atom distance (Å)
_geom_hbond_angle_DHA Donor to H to acceptor angle (°)
_geom_hbond_publ_flag Flag for print request (yes or no)
   
Author requested items  
loop_  
_publ_manuscript_incl_extra_item Additional CIF item submitted for publication
_publ_manuscript_incl_extra_defn Is item defined in Core dictionary? (yes or no)
   
Refinement instructions and input reflection data can now be embedded in the CIF using the following data names  
_iucr_refine_instructions_details
or
_shelx_res_file
_shelx_res_checksum
The instructions used to control the refinement program, e.g. the contents of the SHELXL .res file
_iucr_refine_reflections_details
or
_shelx_hkl_file
_shelx_hkl_checksum
The (unmerged) reflections used as input to the refinement program, e.g. the contents of the SHELXL .hkl file. This could also contain the reflections from more than one twin domain.
_shelx_fab_file
_shelx_fab_checksum
When Platon SQUEEZE is used, a *.fab file is created containing partial structure factors representing the SQUEEZEd region. If this is used together with the ABIN instruction of SHELXL2012, the CIF will automatically contain these two items.
   
Structure-factor lists should be submitted as separate files with the items below  
loop_  
_refln_index_h
_refln_index_k
_refln_index_l
Miller indices h, k and l
_refln_F_meas
_refln_F_squared_meas
(alternate)
Measured F
Measured F2
_refln_F_sigma
_refln_F_squared_sigma
(alternate)
Standard uncertainty of F
Standard uncertainty of F2
_refln_F_calc
_refln_F_squared_calc
(alternate)
Calculated F
Calculated F2
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