XDecomposer: Learning Prior-Free Set Decomposition for Multiphase X-ray Diffraction

TL;DR

XDecomposer is a novel prior-free framework that jointly decomposes and identifies multiphase X-ray diffraction patterns without prior knowledge, significantly improving accuracy and generalization in complex mixtures.

Contribution

It introduces a set prediction approach for multiphase XRD analysis that does not rely on candidate lists or structural templates, enabling more accurate source separation.

Findings

Substantially improves reconstruction accuracy in simulated and experimental datasets.

Maintains strong generalization to unseen chemical mixtures.

Reduces dependence on prior-guided phase matching.

Abstract

Multiphase powder X-ray diffraction (PXRD) analysis remains a fundamental bottleneck in structure identification, as real-world synthesis often produces complex mixtures whose constituent phases (components) cannot be reliably disentangled. While recent advances in representation-based crystal retrieval and generation suggest the possibility of inferring structures directly from PXRD, existing approaches largely assume single-phase inputs and break down in multiphase settings. Here, we present XDecomposer, a prior-free framework for joint decomposition and identification of multiphase XRD patterns without requiring candidate phase lists, structural templates, or prior knowledge of phase number. We formulate multiphase diffraction analysis as a set prediction problem, where the model infers an unordered set of phase-resolved components, their mixture proportions, and corresponding structural representations within a unified architecture. A phase-query-driven decomposition mechanism, together with diffraction-consistent physical reconstruction, enables accurate source separation while preserving crystallographic fidelity. Extensive experiments on both simulated and experimental datasets show that XDecomposer substantially improves reconstruction accuracy and phase identification across diverse chemical systems, while maintaining strong generalization to unseen mixtures. These results provide a practical route toward data-driven, source-resolved multiphase XRD analysis and reduce long-standing dependence on prior-guided iteratively phase matching. The code is openly available at https://github.com/Licht0812/XDecomposer