New neutron time-of-flight (TOF) capability in PDF-4+relational databases: digitized diffraction patterns and I/I-c for quantitative phases analysis

摘要

The PDF-4+ 2016 contains 271 449 entries with atomic coordinates that can be used to calculate neutron time-of-flight (TOF) powder diffraction patterns. These diffraction patterns can all be calculated on-the-fly. Three TOF results can be realized: the live calculation of on-the fly diffraction patterns, the population of static PDF(R) entries, and data for search/match tables for phase identification. In connection with search/match, we have extended the development of the I/Ic formalism to include both constant wavelength (CW) and TOF neutron diffraction data. It is shown that the wavelength dependence of X-ray and CW neutron data must be factored into the behavior of I/Ic, whereas this dependence is directly incorporated into TOF data. (C) 2017 International Centre for Diffraction Data.