SinAE: A Single-Architecture Flow-Matching Autoencoder for Cross-Domain Atomic Systems

TL;DR

SinAE: A single-architecture flow-matching autoencoder significantly reduces reconstruction errors across atomic systems.

cs.LG 🔴 Advanced 2026-07-14 35 views
Yuxuan Ren Fan Yang Jianhua Yao Yatao Bian
autoencoder cross-domain atomic systems flow matching Transformer

Key Findings

Methodology

SinAE employs a vanilla Transformer as both encoder and decoder, utilizing a flow-matching decoder for iterative reconstruction, thus avoiding the need for encoding fine-grained geometry. It achieves near-lossless reconstruction across domains with a unified reconstruction objective.

Key Results

  • On QM9, SinAE achieves a reconstruction RMSD of 0.0002Å, significantly outperforming previous baselines.
  • On MP-20, SinAE's reconstruction RMSD is 0.0017Å, with cross-domain training further enhancing performance.
  • On the CASP15 dataset, SinAE achieves a CA-RMSD of 0.013Å, demonstrating excellent performance.

Significance

SinAE offers high-precision generation of molecules, crystals, and proteins with a unified architecture and training objective, addressing data scarcity issues. Its cross-domain training capability opens new possibilities for chemical and materials science research.

Technical Contribution

SinAE surpasses existing methods by employing a flow-matching decoder for lossless cross-domain reconstruction and achieving cross-domain transfer through a shared atomic latent space.

Novelty

SinAE is the first to achieve lossless reconstruction of molecules, crystals, and proteins under a single architecture, overcoming traditional limitations in architecture and loss functions.

Limitations

  • SinAE requires retraining to handle larger protein structures, limited by current length budgets.
  • Additional symmetry handling may be needed for specific crystal structures.

Future Work

Future research directions include extending SinAE to support larger protein structures and exploring more cross-domain applications.

AI Executive Summary

SinAE is a novel cross-domain atomic system generation method addressing limitations in existing architectures and data scarcity. By using a vanilla Transformer as both encoder and decoder, SinAE achieves high-precision generation of molecules, crystals, and proteins.

The core technology is a flow-matching decoder, which achieves near-lossless reconstruction across domains through iterative refinement, significantly reducing reconstruction errors. Experimental results show outstanding performance on multiple benchmark datasets, particularly on QM9 and MP-20, where its reconstruction RMSD is far below existing baselines.

SinAE's cross-domain training capability opens new possibilities for chemical and materials science research. However, SinAE requires retraining for larger protein structures, which is a key area for future research.

Deep Analysis

Background

Recent advances in atomic system generation have significantly impacted drug discovery, materials design, and protein engineering. However, existing methods are often domain-specific, limiting cross-domain efficiency. Traditional molecular generators rely on equivariant message-passing networks, while crystal generators handle periodic boundary conditions and lattice-basis invariance. Protein generators depend on residue-level parameterization. These methods perform poorly under data scarcity.

Core Problem

Existing generation methods face challenges in handling cross-domain atomic systems, particularly in architecture and loss function design. Achieving high-precision generation of molecules, crystals, and proteins under a single architecture is a pressing issue.

Innovation

SinAE introduces a flow-matching decoder for lossless cross-domain reconstruction. Its innovations include using a vanilla Transformer as both encoder and decoder, avoiding the need for encoding fine-grained geometry. Compared to traditional methods, SinAE offers a more unified approach in architecture and loss functions.

Methodology

  • �� Uses a vanilla Transformer as both encoder and decoder.
  • �� Employs a flow-matching decoder for iterative reconstruction.
  • �� Achieves near-lossless reconstruction across domains with a unified reconstruction objective.
  • �� Enhances rotational robustness with random SO(3) augmentation during training.

Experiments

Experiments were conducted on standard datasets such as QM9, MP-20, and CASP15. Using the Adam optimizer with a learning rate of 10^-4, evaluation metrics included reconstruction RMSD and structure match rate. Results show significant performance improvements across all datasets.

Results

SinAE achieves a reconstruction RMSD of 0.0002Å on QM9 and 0.0017Å on MP-20, significantly outperforming existing baselines. On CASP15, SinAE achieves a CA-RMSD of 0.013Å, demonstrating excellent performance.

Applications

SinAE can be applied in drug discovery for molecular generation, materials science for crystal design, and protein engineering for structure prediction. Its cross-domain training capability offers new possibilities for research in these fields.

Limitations & Outlook

SinAE requires retraining for larger protein structures, limited by current length budgets. Additional symmetry handling may be needed for specific crystal structures. Future research directions include extending SinAE to support larger protein structures and exploring more cross-domain applications.

Plain Language Accessible to non-experts

Imagine you're in a kitchen cooking a meal. Each ingredient has its own characteristics, like vegetables needing to be chopped and meat needing to be marinated. Existing methods are like different kitchen tools, each only handling specific ingredients. SinAE is like a versatile knife that can handle all ingredients, whether chopping, marinating, or cooking. It uses a new cutting technique to ensure each ingredient is perfectly handled without changing tools. This technique saves time and increases efficiency, allowing you to prepare a delicious meal quickly.

ELI14 Explained like you're 14

Hey there! Imagine you're playing a super cool game where you need to build a perfect city. Each building has its own rules, like schools needing quiet areas and shops needing to be near homes. Existing methods are like different building tools, each only able to build specific buildings. SinAE is like a super tool that can build all types of buildings, whether it's schools, shops, or parks. It uses a new building method to ensure each building fits perfectly into the city without changing tools. This way, you save time and make your city more beautiful and efficient!

Glossary

Autoencoder

A neural network used to learn efficient data representations.

SinAE uses an autoencoder for cross-domain atomic system generation.

Flow Matching

An optimization technique to improve reconstruction accuracy in generative models.

SinAE's decoder uses flow matching for iterative reconstruction.

Transformer

A neural network architecture based on attention mechanisms, widely used in NLP.

SinAE uses a vanilla Transformer as both encoder and decoder.

RMSD (Root Mean Square Deviation)

A metric for measuring structural reconstruction accuracy.

SinAE achieves low RMSD across multiple datasets.

Cross-Domain Training

A training method that enables knowledge transfer across different domains through a shared latent space.

SinAE improves performance through cross-domain training.

Open Questions Unanswered questions from this research

  • 1 How can SinAE be extended to support larger protein structures without increasing computational complexity?
  • 2 How can symmetry issues be better addressed in specific crystal structures?

Applications

Immediate Applications

Drug Discovery

SinAE can be used to generate novel molecular structures, accelerating drug development.

Long-term Vision

Materials Design

SinAE's cross-domain generation technology can aid in designing new materials with specific properties.

Abstract

Small molecules, crystals, and proteins all reduce to atoms in 3D space, yet their generative pipelines remain fragmented across domains, each with its Small molecules, crystals, and proteins all reduce to atoms in 3D space, yet their generative pipelines remain fragmented across domains, each with its own graph, equivariant, or frame-based architecture. Cross-domain training would mitigate per-domain data scarcity, but direct generation in 3D coordinate space cannot easily handle the heterogeneous structural priors of all three domains, and no prior latent autoencoder is simultaneously lossless and architecturally general across all three. We introduce SinAE, a single-architecture flow-matching autoencoder for molecules, crystals, and proteins, with vanilla Transformer encoder and decoder and no equivariant, graph, or domain-specific operators. Rather than requiring the encoder to capture fine-grained geometry, SinAE shifts the reconstruction burden into an iterative flow-matching decoder, achieving near-lossless reconstruction across domains and reducing reconstruction errors by orders of magnitude relative to prior latent baselines. The same per-token latent supports a standard Diffusion Transformer prior that reaches strong performance on molecular, crystal, and protein generation benchmarks. Joint molecule--crystal training strictly improves both domains, providing direct evidence of cross-domain transfer through a shared atomic latent. Code is available at https://github.com/BlueWhaleLab/SinAE .

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