Agreement factors based on the ratio of intensities R
collected in dynamic structure pump–probe crystallography experiments are shown to be analogous to the
factors widely used in standard crystallographic refinements. Fourier photodifference maps allow the visualization of the externally induced structural changes in the crystal, but also can be used during refinement to monitor its progress. Photodeformation maps are modified to separate the photo-induced structural change from the effect of the temperature increase on laser exposure.