Scatman

Scatman simulates and iteratively fits wide-angle coherent diffraction imaging (CDI) single-shot patterns to retrieve three-dimensional morphological information from isolated nanoscale objects such as viruses, aerosols, nanocrystals, and droplets.

Key Features:

• Approximate numerical simulation: Provides an approximate yet fast numerical method for simulating wide-angle scattering images and supporting iterative fitting.
• Multi-slice Fourier transform: Uses the multi-slice Fourier transform method to compute scattering patterns while partially incorporating optical effects.
• Wide-angle coverage: Handles scattering angles exceeding approximately 10° relevant to wide-angle CDI.
• Iterative forward fitting: Supports iterative forward-fitting of single-shot diffraction patterns using scattering simulations.
• Target sample types: Applicable to isolated nanoscale objects including viruses, aerosols, nanocrystals, and droplets.
• Weak-interaction regime: Optimized for small, isolated samples that exhibit weak interactions.
• Computational performance: Implementation (PyScatman) demonstrates generation of wide-angle scattering patterns in milliseconds.

Scientific Applications:

• 3D morphology retrieval: Retrieval of three-dimensional shape and morphological information from single-shot wide-angle CDI patterns.
• Forward-fitting-based shape retrieval: Forward-fitting-based shape retrieval tasks for isolated nanoparticles and similarly sized objects.
• Characterization of nanoscale structures and dynamics: Characterization of structural features and dynamics in viruses, aerosols, nanocrystals, and droplets from wide-angle scattering data.
• Analysis of wide-angle CDI experiments: Enables rapid simulation-driven analysis schemes for wide-angle coherent diffraction experiments.

Methodology:

Computes scattering patterns using a multi-slice Fourier transform method that partially incorporates optical effects and applies an approximate numerical forward model for iterative forward-fitting of single-shot wide-angle CDI patterns.