Saved in:
Bibliographic Details
Main Authors: Baggett, Elizabeth J., Friedman, Edward G., Shetty, Abhishek, Chan-Sew, Derrick, Acha, Vanellsa, Dwarcherla, Harshita, Kienzle, Paul, Ratcliff, William
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.23811
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913063287914496
author Baggett, Elizabeth J.
Friedman, Edward G.
Shetty, Abhishek
Chan-Sew, Derrick
Acha, Vanellsa
Dwarcherla, Harshita
Kienzle, Paul
Ratcliff, William
author_facet Baggett, Elizabeth J.
Friedman, Edward G.
Shetty, Abhishek
Chan-Sew, Derrick
Acha, Vanellsa
Dwarcherla, Harshita
Kienzle, Paul
Ratcliff, William
contents Determining crystal symmetry from powder X-ray diffraction is a central problem in materials characterization, yet multiple space groups can produce indistinguishable patterns, making automated classification difficult. We show that attention-based architectures, while superior to convolutional networks for this task, are insufficient on their own: reliable symmetry extraction requires encoding crystallographic knowledge into both the network architecture and the training curriculum. We introduce a physics-informed transformer that classifies powder patterns into 99 extinction groups, the most specific symmetry classification accessible from diffraction data alone, using an explicit sin^2(theta) coordinate channel, physics-aware positional encoding, and a structured multi-task decoder that separates geometric rule learning from holistic pattern recognition. A three-stage curriculum of balanced synthetic pretraining, realistic fine-tuning with explicit preferred-orientation modeling, and Bayesian prior injection proves essential for bridging the synthetic-to-real domain gap, while post-hoc temperature scaling rather than additional training is the key remaining ingredient for robust real-data transfer. By mapping predictions onto the directed acyclic graph of maximal translationengleiche subgroups, we show that the calibrated model's errors are not random but physically structured: they remain local on the subgroup hierarchy and flow predominantly toward lower-symmetry descendants, consistent with the physical erasure of systematic-absence cues by real-world noise. These results establish that physics-informed target design, curriculum, and calibrated inference matter as much as model capacity for scientific machine learning on diffraction data.
format Preprint
id arxiv_https___arxiv_org_abs_2604_23811
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Attention Is Not All You Need for Diffraction
Baggett, Elizabeth J.
Friedman, Edward G.
Shetty, Abhishek
Chan-Sew, Derrick
Acha, Vanellsa
Dwarcherla, Harshita
Kienzle, Paul
Ratcliff, William
Materials Science
Determining crystal symmetry from powder X-ray diffraction is a central problem in materials characterization, yet multiple space groups can produce indistinguishable patterns, making automated classification difficult. We show that attention-based architectures, while superior to convolutional networks for this task, are insufficient on their own: reliable symmetry extraction requires encoding crystallographic knowledge into both the network architecture and the training curriculum. We introduce a physics-informed transformer that classifies powder patterns into 99 extinction groups, the most specific symmetry classification accessible from diffraction data alone, using an explicit sin^2(theta) coordinate channel, physics-aware positional encoding, and a structured multi-task decoder that separates geometric rule learning from holistic pattern recognition. A three-stage curriculum of balanced synthetic pretraining, realistic fine-tuning with explicit preferred-orientation modeling, and Bayesian prior injection proves essential for bridging the synthetic-to-real domain gap, while post-hoc temperature scaling rather than additional training is the key remaining ingredient for robust real-data transfer. By mapping predictions onto the directed acyclic graph of maximal translationengleiche subgroups, we show that the calibrated model's errors are not random but physically structured: they remain local on the subgroup hierarchy and flow predominantly toward lower-symmetry descendants, consistent with the physical erasure of systematic-absence cues by real-world noise. These results establish that physics-informed target design, curriculum, and calibrated inference matter as much as model capacity for scientific machine learning on diffraction data.
title Attention Is Not All You Need for Diffraction
topic Materials Science
url https://arxiv.org/abs/2604.23811