Collaborative Research: CDS&E: Charge-density based ML framework for efficient exploration and property predictions in the large phase space of concentrated materials

未来的工程应用需要复杂的材料来承受极端环境。电子结构计算在发展对材料的原子和电子级性质的基本理解方面起着不可或缺的作用。为了应对不断增长的材料复杂性的挑战，在这个项目中，克莱姆森大学的研究人员将与科罗拉多矿业学院的研究人员合作，将基于数据科学的图像识别技术与电子结构计算相结合，以预测材料特性。图像识别广泛应用于人脸识别、车道辅助驾驶、食品污染物检测、癌细胞检测等领域。在这个项目中，材料的电荷密度将以图像的形式来学习材料的电子结构，从而在复杂材料中进行性能预测。该项目将有助于技术、教育和劳动力的发展。本课程将提供对复杂合金晶格畸变的基本理解，即由多种主要元素组成的高浓度高熵合金。该项目将开发一个开源的机器学习框架，其中包含电荷密度和合金特性的数据库。它还将通过新的“材料科学中的数据科学”课程和夏季研讨会，在材料物理学和数据科学的交叉领域培养本科生和研究生，以适应未来的数字经济。高熵合金中的化学随机性产生了独特的最近邻环境，导致晶格和电子扭曲，从而导致定性和定量性质的巨大不确定性。不确定性尺度具有组成（原子分数）和化学（不同元素）的多样性，这给密度泛函理论（DFT）探索相空间带来了极其严峻的挑战。这一技术挑战与成分-性质相关性的机制原因的科学挑战是平行的。由于电荷密度是可以从中提取物理和性质相关性的基本量，因此研究人员将开发基于电荷密度的机器学习框架，以阐明破坏性能量景观对新兴性质的作用，同时消除追踪大相的瓶颈。机器学习模型将从简单合金中学习电荷密度分布和性质，并在复杂合金中预测它们，同时完全绕过昂贵的DFT计算。研究人员将在电荷密度较大的不对称性导致性质较大不确定性的假设下进行研究。学生将学习进行电子结构计算，数据生成和解释，以及应用机器学习模型来预测材料特性。学生还将学习应用于材料科学问题的图像识别技术。调查人员将组织夏季研讨会，以互动、参与和实践的方式让女孩参与STEM。研究人员还将组织一个虚拟研讨会，特别关注材料预测的特征识别技术。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical summaryFuture engineering applications require complex materials to withstand extreme environments. Electronic structure calculations have played an integral role in developing fundamental understanding of atomic and electronic level properties of materials. To tackle the challenges of growing materials complexities, in this project, the investigator at Clemson University will collaborate with investigators at Colorado School of Mines to integrate data-science based image-recognition techniques with electronic structure calculations to predict materials properties. Image recognition is widely used for face recognition, lane-assisted driving, food-contaminant detection, cancer-cell detection, etc. In this project, the charge density of materials will be used in the form of images to learn the electronic structure of materials to enable property predictions in complex materials. The project will contribute to technical, educational and workforce development. A fundamental understanding of lattice distortion in complex alloys will be delivered, namely in high entropy alloys that consist of multiple principal elements in large concentrations. The project will develop an open-source machine learning framework with a curated database of charge densities and alloys’ properties. It will also train undergraduate and graduate students for future digital economy at the intersection of materials physics and data science via a new ‘data science in materials science’ course, and summer workshops.Technical summaryThe chemical randomness in high entropy alloys engenders unique nearest neighbor environments causing lattice and electronic distortions that result in large uncertainties in properties both qualitatively and quantitively. The uncertainties scale with compositional (atomic fraction) and chemical (different elements) diversities resulting in an extremely stiff challenge for density functional theory (DFT) to explore the phase space. This technical challenge runs parallel to the scientific challenge of mechanistic reasons of composition-property correlations. Since, charge density is the fundamental quantity from which the physics and property correlations can be extracted, the investigators will develop a charge-density based machine learning framework that will elucidate the role of disruptive energy landscape on the emerging properties, and simultaneously remove the bottleneck to trace the large phase. The machine learning models will learn the charge density distributions and properties from simpler alloys and predict them in complex alloys while bypassing expensive DFT calculations altogether. The investigators will work under the hypothesis that larger asymmetry in charge density leads to larger uncertainty in properties. The students will learn to perform electronic structure calculations, data generation and interpretation, and application of machine learning models to predict materials properties. The students will also learn image-recognition techniques applied to materials science problems. Summer workshops will be organized by the investigators to engage girls in STEM with an interactive, engaging and hands-on approach. The investigators will also organize a virtual workshop with a specific focus on feature recognition techniques for materials predictions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.