Analysis of multicrystal pump–probe data sets. I. Expressions for the RATIO model

摘要

The RATIO method in time-resolved crystallography [Coppens et al. (2009). J. Synchrotron Rad. >16, 226–230] was developed for use with Laue pump–probe diffraction data to avoid complex corrections due to wavelength dependence of the intensities. The application of the RATIO method in processing/analysis prior to structure refinement requires an appropriate ratio model for modeling the light response. The assessment of the accuracy of pump–probe time-resolved structure refinements based on the observed ratios was discussed in a previous paper. In the current paper, a detailed ratio model is discussed, taking into account both geometric and thermal light-induced changes.