SFX analysis of non-biological polycrystalline samples

Area of Science:

• Crystallography
• Materials Science
• Analytical Chemistry

Background:

• Serial femtosecond crystallography (SFX) traditionally requires single crystals.
• X-ray powder diffraction (XPD) is limited in resolving complex structures from mixtures.
• Nanoscale polycrystalline samples pose challenges for traditional crystallographic methods.

Purpose of the Study:

• To evaluate the potential of SFX for analyzing polycrystalline samples.
• To demonstrate the ability of SFX to differentiate and process data from multiple crystalline components within a mixture.
• To assess the feasibility of solving crystal structures from SFX data of nanoscale polycrystalline zeolites.

Main Methods:

• Simulating X-ray diffraction snapshots from a mixture of two zeolites (100-300 nm grain size) using SFX.
• Processing simulated SFX data with the CrystFEL software suite.
• Utilizing primitive unit-cell volume from individual snapshots for subset separation.
• Applying Monte Carlo integration and direct methods (SHELXD) for structure solution.

Main Results:

• SFX data successfully separated into two subsets corresponding to the individual zeolites.
• 3D single-crystal diffraction intensities were obtained for each zeolite.
• Crystal structures of both zeolites were readily solved from the processed SFX data.
• Demonstrated the effectiveness of CrystFEL for analyzing complex polycrystalline datasets.

Conclusions:

• SFX is a powerful technique for collecting 3D diffraction data from polycrystalline materials.
• This approach significantly enhances the capabilities of X-ray powder diffraction.
• SFX enables the separation and structural analysis of multiple crystalline phases in a mixture.
• The method provides a viable route for solving crystal structures from nanoscale polycrystalline samples.