SPIND-TC

SPIND-TC extends the Sparse Pattern INDexing (SPIND) algorithm to index two-color X-ray free-electron laser diffraction patterns, enabling accurate indexing of dual-wavelength datasets for protein structure determination.

Key Features:

• Two-Color Data Handling: Processes diffraction data from two-color X-ray free-electron laser sources, enabling analysis of dual-wavelength diffraction patterns.
• Sparse-Pattern Indexing: Extends SPIND sparse-pattern indexing capability to two-color data and can index patterns with as few as five peaks.
• Algorithmic Adaptation: Adapts the sparse-pattern indexing approach to accommodate identification and indexing of diffraction peaks across two wavelengths.
• Support for Advanced Experiments: Enables analysis applicable to X-ray pump/X-ray probe experiments and multiple-wavelength anomalous dispersion phasing methods.
• Validation: Demonstrated performance on simulated and experimental diffraction datasets of protein crystals.

Scientific Applications:

• Structural Biology: Indexes two-color XFEL diffraction data to support protein structure determination from protein crystals.
• Pump–Probe Studies and MAD Phasing: Supports workflows for X-ray pump/X-ray probe experiments and multiple-wavelength anomalous dispersion phasing at X-ray free-electron laser facilities.
• Dual-Wavelength Diffraction Analysis: Facilitates analysis of complex dual-wavelength diffraction patterns arising in experiments at two-color XFELs.

Methodology:

Extension of the Sparse Pattern INDexing (SPIND) algorithm to two-color data; sparse-pattern indexing applied to patterns with as few as five peaks; algorithmic adjustments for identification and indexing of peaks across two wavelengths; validation on simulated and experimental protein-crystal diffraction datasets.