Should we have a table of d spacing, intensity, hkl in HPDF? - pdera/HPDF-file-format GitHub Wiki
B. Chen
That’s very good discussion. One thing worth mentioning is whether we would like to have DIHKL list for the JCPDS file. If we extend the CIF format to include the eos information, the DIHKL values is not needed because the values can be calculated using the information available in the CIF file. However, there are scenarios some users may want to edit the DIHKL list (i.e., deleting some low intensity peaks for clarity in the plot). If we choose to keep the DIHKL list, their values will need to cross checked from the lattice parameters in the file.
One day workshop on this important issue is a good idea.
- Should we use CIF directly rather than table values of intensity from 1 bar diffraction pattern? Should we have a separate EOS data file and packaging it together with CIF? About this question, I like the idea of a separate EOS data file and packaging it together with CIF. The table values of intensity from 1 bar diffraction pattern can be optional and included in the separate EOS data file. There may be scenarios that we do not have structural resolution to an unknown mineral, but the d-spacing and intensity information is available from the x-ray diffraction pattern.
K. Dziubek
One question I would like to ask Przemek and the software developers: Przemek made a suggestion that d-spacing info for diffraction peaks is redundant and can be actually removed. While calculating the peak positions for given unit cell and space group (concerning also systematic absences) is rather trivial, calculating peak intensities require giving the specific chemical composition (think about difficult cases as e.g. non-stoichiometric phases) and requires some maths to calculate structure factors for individual reflections. It is not a problem to remove the list of reflections from the JCPDS files, but the question remains if the routines for calculating the reflection intensities could be easily introduced into existing software.