X-ray diffraction (XRD) data acquisition and analysis is among the most
time-consuming steps in the development cycle of novel thin-film materials. We
propose a machine-learning-enabled approach to predict crystallographic
dimensionality and space group from a limited number of thin-film XRD patterns.
We overcome the scarce-data problem intrinsic to novel materials development by
coupling a supervised machine learning approach with a model agnostic,
physics-informed data augmentation strategy using simulated data from the
Inorganic Crystal Structure Database (ICSD) and experimental data. As a test
case, 115 thin-film metal halides spanning 3 dimensionalities and 7
space-groups are synthesized and classified. After testing various algorithms,
we develop and implement an all convolutional neural network, with cross
validated accuracies for dimensionality and space-group classification of 93%
and 89%, respectively. We propose average class activation maps, computed from
a global average pooling layer, to allow high model interpretability by human
experimentalists, elucidating the root causes of misclassification. Finally, we
systematically evaluate the maximum XRD pattern step size (data acquisition
rate) before loss of predictive accuracy occurs, and determine it to be
0.16{\deg}, which enables an XRD pattern to be obtained and classified in 5.5
minutes or less.

本研究针对开发新薄膜材料中最耗时的 X 射线衍射数据收集和分析提出了机器学习模型，该模型可以从有限数量的薄膜 XRD 模式中预测结晶维度和空间群，并使用模型无关的物理驱动数据扩充策略来克服材料开发中固有的稀缺数据问题，经过测试，该模型具有 93% 和 89% 的维数和空间群分类交叉验证精度。