Towards pump-probe single-crystal XFEL refinements for small-unit-cell systems

Area of Science:

• Crystallography
• Structural Biology
• Materials Science

Background:

• Serial femtosecond crystallography (SFX) has potential for small-unit-cell systems.
• Limited application due to lack of reliable data reduction methods.
• Accurate crystal orientation determination is crucial for intensity corrections.

Purpose of the Study:

• Develop an automated data reduction pipeline for small-unit-cell SFX.
• Address challenges in data processing for these systems.
• Enable new scientific investigations using SFX.

Main Methods:

• Developed a pipeline for automated data reduction from spot harvesting to merged structure factors.
• Utilized sparse indexing, seed-skewness integration, and advanced intensity corrections.
• Implemented overlap-based Ewald sphere width and partiality correction with dynamic post-refinement.

Main Results:

• Successfully reduced data for K4[Pt2(P2O5H2)4]·2H2O using the pipeline.
• Solved the crystal structure to an R1 factor of ~9.1%.
• Demonstrated the pipeline's capability for challenging small-unit-cell systems.

Conclusions:

• The developed pipeline significantly advances small-unit-cell SFX.
• It is expected to facilitate studies of excited states and reaction intermediates.
• Opens new avenues for structural analysis in challenging systems.