论文标题
材料特性外推的原子系统的小波散射网络
Wavelet Scattering Networks for Atomistic Systems with Extrapolation of Material Properties
论文作者
论文摘要
材料科学中机器学习的梦想是使模型学习原子系统的基本物理,从而使其超越了训练集的插值,以预测原始培训数据中不存在的属性。除了在机器学习体系结构和训练技术方面取得进步,实现这一雄心勃勃的目标还需要一种方法将3D原子系统转换为特征表示,该特征表示可以保留旋转和翻译对称性,在小小的扰动下的平稳性以及在重新订购下的不变性。原子轨道小波散射的变换通过构造保留了这些对称性,并取得了巨大的成功,作为机器学习能量预测的特征方法。无论是在小分子还是在散装的无定形$ \ text {li}_α\ text {si} $系统中,使用小波散射系数作为特征的机器学习模型表明,在计算成本的一小部分中,与密度功能理论相当的精度。在这项工作中,我们测试了我们的$ \ text {li}_α\ text {si} $能量预测因子的概括性的属性,这些属性不包含在训练集中的属性,例如弹性常数和迁移屏障。我们证明,统计特征选择方法可以减少过度拟合,并导致这些外推任务的准确性。
The dream of machine learning in materials science is for a model to learn the underlying physics of an atomic system, allowing it to move beyond interpolation of the training set to the prediction of properties that were not present in the original training data. In addition to advances in machine learning architectures and training techniques, achieving this ambitious goal requires a method to convert a 3D atomic system into a feature representation that preserves rotational and translational symmetry, smoothness under small perturbations, and invariance under re-ordering. The atomic orbital wavelet scattering transform preserves these symmetries by construction, and has achieved great success as a featurization method for machine learning energy prediction. Both in small molecules and in the bulk amorphous $\text{Li}_α\text{Si}$ system, machine learning models using wavelet scattering coefficients as features have demonstrated a comparable accuracy to Density Functional Theory at a small fraction of the computational cost. In this work, we test the generalizability of our $\text{Li}_α\text{Si}$ energy predictor to properties that were not included in the training set, such as elastic constants and migration barriers. We demonstrate that statistical feature selection methods can reduce over-fitting and lead to remarkable accuracy in these extrapolation tasks.