PDDFormer: Pairwise Distance Distribution Graph Transformer for Crystal Material Property Prediction
Xiangxiang Shen, Zheng Wan, Lingfeng Wen, Licheng Sun, Jian Yang, Xuan Tang, Shing-Ho J. Lin, Xiao He, Mingsong Chen, Xian Wei

TL;DR
This paper introduces WPDDFormer, a novel graph transformer that uses pairwise distance distributions to improve crystal property prediction, addressing the issues of discontinuity and high computational costs in traditional methods.
Contribution
The paper proposes atom-Weighted and Unit cell PDDs integrated into a graph transformer, enhancing stability and efficiency in crystal property prediction.
Findings
Achieves state-of-the-art accuracy on Materials Project and JARVIS-DFT datasets.
Demonstrates robustness of crystal graphs under atomic perturbations.
Reduces computational costs compared to traditional PDD methods.
Abstract
Crystal structures can be simplified as a periodic point set that repeats across three-dimensional space along an underlying lattice. Traditionally, crystal representation methods characterize the structure using descriptors such as lattice parameters, symmetry, and space groups. However, in reality, atoms in materials always vibrate above absolute zero, causing their positions to fluctuate continuously. This dynamic behavior disrupts the fundamental periodicity of the lattice, making crystal graphs based on static lattice parameters and conventional descriptors discontinuous under slight perturbations. Chemists proposed the pairwise distance distribution (PDD) method to address this problem. However, the completeness of PDD requires defining a large number of neighboring atoms, leading to high computational costs. Additionally, PDD does not account for atomic information, making it…
Peer Reviews
Decision·ICLR 2025 Conference Withdrawn Submission
1. The WPDDFormer model consistently outperforms other state-of-the-art methods across multiple tasks on the JARVIS and Materials Project datasets, demonstrating its effectiveness. 2. The authors provide theoretical guarantees on the continuity and completeness of the WPDD-based graphs, ensuring robust performance under minor structural perturbations.
I have no major concerns with this paper; however, an ablation study on the effect of varying the radius on WPDDFormer’s performance and efficiency would provide valuable insights into its scalability. Additionally, a time comparison between WPDDFormer and UPDDFormer would strengthen the evidence supporting UPDDFormer’s efficiency claims.
Originality: This work makes very significant novelty contributions in combining pairwise distance distribution with machine learning based crystal property prediction. Quality: The quality of this work is evidenced by good theoretic analysis and strong experiment results. Clarity: The writing of this work is overall good and clear. Significance: The idea of efficiently integrating pairwise distance distribution into transformer model proposed by this work is insightful and enlightnin
(1) A remarkable motivation of this work is described in Abstract "However, in reality, atoms in material always vibrate above absolute zero, causing continuous fluctuations in their positions" (line 15-17). But it seems there is no clear discussion why the use of pairwise distance distribution resolves this atom position fluctuation issue? Authors are encouraged to give detailed clarification or discussions to this question. (2) Generally, two novelty contributions are proposed in this work, i
1. The proposed crystal representation demonstrates continuity under small distortions and perturbations, which can be advantageous for robustness.
1. Incomplete and Potentially Misleading Claims about Completeness The completeness proof in the paper relies on the assumption that the PDD matrix acts as a generally complete invariant for distinguishing different crystal structures. However, this is inaccurate. The PDD matrix is not guaranteed to distinguish unstable crystal structures and cannot differentiate between chiral crystal structures, indicating limitations in the claimed theoretical foundation. Action suggested: reorganize the pr
- The proposed (W/U)PDDs incorporate atomic information into PDD and address its high computational cost. - The paper is overall well-written with nice flow, clarity, and illustrations.
- The experimentation focuses on relatively simple scalar properties, some of which do not physically depend on crystal periodicity. - Incorporating PDD into crystal graphs makes the data physics-informed, however, the proposed model does not seem to consider interpretability. - Minor issues - In Definition 1, I suggest using boldface or other methods to help distinguish scalar, vector, and matrix. - Some languages in Definitions are vague: (1) Line 133, the range of what “crystal graph” ref
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Taxonomy
TopicsMachine Learning in Materials Science · Gene expression and cancer classification · Bioinformatics and Genomic Networks
MethodsAttention Is All You Need · Dense Connections · Laplacian EigenMap · Label Smoothing · Dropout · Linear Layer · Laplacian Positional Encodings · Layer Normalization · Byte Pair Encoding · Adam
