IOTA: integration optimization, triage and analysis tool for the processing of XFEL diffraction images

Serial femtosecond crystallography (SFX) uses an X‐ray free‐electron laser to extract diffraction data from crystals not amenable to conventional X‐ray light sources owing to their small size or radiation sensitivity. However, a limitation of SFX is the high variability of the diffraction images that are obtained. As a result, it is often difficult to determine optimal indexing and integration parameters for the individual diffraction images. Presented here is a software package, called IOTA, which uses a grid‐search technique to determine optimal spot‐finding parameters that can in turn affect the success of indexing and the quality of integration on an image‐by‐image basis. Integration results can be filtered using a priori information about the Bravais lattice and unit‐cell dimensions and analyzed for unit‐cell isomorphism, facilitating an improvement in subsequent data‐processing steps. An integration optimization, triage and analysis tool (IOTA) is presented, which uses a grid‐search approach to maximize the success of indexing and integrating serial X‐ray free‐electron laser diffraction images. IOTA also includes several useful tools for on‐site diffraction data processing.