标题： 通过对称性约束扩散模型发现二维材料 显示英文标题

标题： Discovery of 2D Materials via Symmetry-Constrained Diffusion Model

摘要： 二维材料的生成模型在加速材料发现过程中显示出巨大潜力。这些材料的稳定性和性能与其潜在的对称性密切相关。然而，现有的二维材料生成模型往往忽略了对称性约束，这限制了生成结构的多样性和质量。在这里，我们引入了一种对称性约束扩散模型（SCDM），该模型将空间群对称性整合到生成过程中。通过结合Wyckoff位置，该模型确保遵循对称性原则，从而生成了2000个候选结构。进行了密度泛函理论（DFT）计算以评估这些结构在结构弛豫后的凸包能量。从生成的样本中，确定了843种满足能量稳定性标准（Ehull < 0.6 eV/原子）的材料。其中，选择了六个候选者进行进一步的稳定性分析，包括声子能带结构评估和电子性质研究，所有这些候选者均表现出声子谱稳定性。为了评估SCDM的性能，还通过晶体结构预测模型评估了一个无对称约束的扩散模型。结果表明，引入对称性约束增强了生成的二维材料的有效性，为通过生成建模发现二维材料做出了贡献。 显示英文摘要

摘要： Generative model for 2D materials has shown significant promise in accelerating the material discovery process. The stability and performance of these materials are strongly influenced by their underlying symmetry. However, existing generative models for 2D materials often neglect symmetry constraints, which limits both the diversity and quality of the generated structures. Here, we introduce a symmetry-constrained diffusion model (SCDM) that integrates space group symmetry into the generative process. By incorporating Wyckoff positions, the model ensures adherence to symmetry principles, leading to the generation of 2,000 candidate structures. DFT calculations were conducted to evaluate the convex hull energies of these structures after structural relaxation. From the generated samples, 843 materials that met the energy stability criteria (Ehull < 0.6 eV/atom) were identified. Among these, six candidates were selected for further stability analysis, including phonon band structure evaluations and electronic properties investigations, all of which exhibited phonon spectrum stability. To benchmark the performance of SCDM, a symmetry-unconstrained diffusion model was also evaluated via crystal structure prediction model. The results highlight that incorporating symmetry constraints enhances the effectiveness of generated 2D materials, making a contribution to the discovery of 2D materials through generative modeling.