X-Ray Powder Diffraction

3.0 Refined powder diffraction data (where atomic coordinates have been determined)

3.1 Presentation of data in the manuscript

3.1.1 Description. If the procedures for data collection and structure analysis were routine, their description should be particularly concise. When the analysis has not been of a routine nature, the authors should briefly detail the procedures used. In most cases a table of atomic coordinates may be provided which should give details of occupancies that are less than unity. Anisotropic thermal parameters may be included if they form an important aspect of the study. Selected bond lengths and angles, with estimated standard deviations, should be given as tables in full papers, or in the figure caption for communications. 

3.1.2 Illustrations. For Rietveld refinements, an observed + calculated + difference profile plot should normally be given for each structure determination, except where a significant number of similar refinements have been carried out. In such cases, only the minimum number of representative plots should be included in the article, with additional plots being provided as supplementary material.

A conventional line drawing of the structure should normally be included except in the simplest cases and one perspective diagram (or stereo pair) if appropriate. Packing diagrams should not be included unless required to illustrate a specific chemical point. The atom numbering scheme should be clearly shown in one of the diagrams. Any differences from that required by standard rules of chemical nomenclature should be pointed out. Each atom of the asymmetric unit should be assigned an arabic numeral in parentheses following the chemical symbol: C(2), O(1''), etc.; it is often convenient to associate a particular number of primes with a particular asymmetric unit. Alternatively, roman numeral superscripts can be employed: C(2I)···C(2IV). For e-only journals, authors are encouraged to provide 3D interactive versions of their figures. 

3.1.3 Data required for presentation in the manuscript. The following information should be given in the manuscript: 

• Diffractometer name and model
• Radiation wavelength ()
• Temperature of data collection
• Step size
• Chemical formula and formula weight (M)
• Unit cell dimensions ( or pm, degrees)
• Space group
• Z
• Number of reflections
• Final R values (R_wp, R_exp and R_I) and method of background treatment    

Where a Rietveld refinement has been performed, the visual fit is normally required. This can be displayed in the ESI if it is not of primary importance to the paper. For full papers the data should be given in either textual or tabular format, whereas for communications data should be given in a footnote or in the References/Notes section.

3.2 Supplementary material required for assessment and/or deposition

3.2.1 Submitting data to the RSC. Authors may submit supplementary crystallographic data as a Crystallographic Information File (CIF) file via the RSC ReSourCe service. Authors should combine multiple data sets for a given manuscript into a single file. This will minimise the chance that files will be misplaced or associated with the wrong manuscript. The individual structures in the combined file must be separated from each other by the sequence #===END at the beginning of a line. Authors must identify which manuscript the electronic file is associated with when they submit the file by entering the name of the manuscript at the top of the electronic file. The information required for deposition includes: 

• A table of final fractional atomic coordinates
• Any calculated coordinates (e.g. hydrogen)
• A full list of bond lengths and angles with estimated standard deviations
• A full list of displacement parameters in the form B_ij or U_ij (in ² or pm²)
• FULL details of the refinement.
• Profile difference plots for all analyses. Where a range of similar analyses are presented a minimum number of representative plots may be given    

Tables of structure factors (F_o, F_c) should not be sent, but copies should be retained by the authors so that they may be made available via the Editorial Office if requested. If the data are not available in electronic form then two hard copies of items detailed above should be included with the paper at the time of submission. 

3.2.2 Deposition of material at the Cambridge Crystallographic Data Centre. The Editorial Office will forward the deposited CIF to the Cambridge Crystallographic Data Centre (CCDC) once the paper has been accepted. Enquiries for data should be directed via the CCDC-please include the relevant CCDC numbers with your enquiries.