MiAD: Mirage Atom Diffusion for De Novo Crystal Generation
Andrey Okhotin, Maksim Nakhodnov, Nikita Kazeev, Andrey E Ustyuzhanin, Dmitry Vetrov

TL;DR
MiAD introduces mirage infusion, a technique that allows diffusion models to dynamically alter the number of atoms in crystal generation, significantly improving quality and state-of-the-art S.U.N. rates in de novo crystal design.
Contribution
The paper presents mirage infusion, enabling diffusion models to change atom counts during crystal generation, enhancing variability and performance.
Findings
Model quality improved by up to 2.5x with mirage infusion.
Achieved 8.2% S.U.N. rate on MP-20 dataset.
Outperforms existing state-of-the-art methods.
Abstract
In recent years, diffusion-based models have demonstrated exceptional performance in searching for simultaneously stable, unique, and novel (S.U.N.) crystalline materials. However, most of these models don't have the ability to change the number of atoms in the crystal during the generation process, which limits the variability of model sampling trajectories. In this paper, we demonstrate the severity of this restriction and introduce a simple yet powerful technique, mirage infusion, which enables diffusion models to change the state of the atoms that make up the crystal from existent to non-existent (mirage) and vice versa. We show that this technique improves model quality by up to compared to the same model without this modification. The resulting model, Mirage Atom Diffusion (MiAD), is an equivariant joint diffusion model for de novo crystal generation that is capable of…
Peer Reviews
Decision·Submitted to ICLR 2026
Strengths: - The paper is well written and easy to understand. Related works have been discussed properly. - The method is generalizable and can be applied to most pre-existing works without much hassle. - Results show the improvement in SUN metrics, although the unique and novel metrics are not better than baselines like FlowMM, DiffCSP and WyFormer.
Weaknesses: - This work only introduces a representation for a material that allows the number of atoms to be flexible. No new model architecture or algorithmic variation has been proposed, which limits the novelty of this work. - Datasets with bigger and more complicated structures should have been used to highlight the advantages of this approach. Please also include the results of MPTS-52 dataset in the table. - As noted in the ablation studies, the method is sensitive to hyperparameters.
The paper is well written and the idea is simple yet powerful, resulting in a significant improvement of S.U.N rate in the DNG task by keeping the same backbone architecture as some of the baseline model. Additionally, the authors provide ablation studies for all key design choices, with detailed results reported in the appendix. The evaluation of the generated crystalline material samples is conducted both by DFT calculation and machine-learning based interatomic potentials.
I have the feeling that the contribution may be somewhat limited, even though it appears to provide a benefit in terms of the S.U.N. rate. In addition to [1] there is another concurrent work [2] (also out in August) that uses virtual or fake nodes for molecules to allow for variable-sized output. In this paper, the idea is applied to materials, although it is not material-specific and could, in principle, be extended to any graph generation problem. As noted in the paper, the authors mask the m
- The paper is very well written. The limitation of fixed atom counts in current crystal diffusion models is well identified and practically significant for de novo materials discovery. - The idea of mirage infusion technique is conceptually simple yet effective, implemented by augmenting the atom-type diffusion process with an additional “mirage” type and masking loss terms appropriately. It Gives the flexibility to the models to vary the number of atoms in a crystal during the generation proce
- The paper lacks methodological novelty. MiAD’s architecture remains largely identical to DiffCSP, with the only change being the addition of mirage atoms. While this tweak is clever, it is incremental rather than fundamentally new. - The paper does not convincingly justify why varying atom numbers is scientifically important beyond improving diversity. For instance, how does this help in discovering more stable or experimentally realizable materials? - The paper could benefit from qualitative
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Taxonomy
TopicsMachine Learning in Materials Science · Model Reduction and Neural Networks · Generative Adversarial Networks and Image Synthesis
