Developing an improved Crystal Graph Convolutional Neural Network framework for accelerated materials discovery

TL;DR

This paper introduces an improved crystal graph convolutional neural network (iCGCNN) that enhances accuracy and efficiency in materials discovery by integrating structural and chemical information, significantly outperforming previous models in predicting stability and aiding high-throughput searches.

Contribution

The authors develop an enhanced CGCNN model (iCGCNN) incorporating Voronoi tessellation, 3-body correlations, and optimized bonds, leading to superior predictive accuracy and accelerated materials screening.

Findings

iCGCNN achieves 20% higher accuracy than original CGCNN on DFT data.

The success rate in high-throughput search increases by 310 times with iCGCNN.

Identified 97 new stable compounds from screening 132,600 candidates.

Abstract

The recently proposed crystal graph convolutional neural network (CGCNN) offers a highly versatile and accurate machine learning (ML) framework by learning material properties directly from graph-like representations of crystal structures ("crystal graphs"). Here, we develop an improved variant of the CGCNN model (iCGCNN) that outperforms the original by incorporating information of the Voronoi tessellated crystal structure, explicit 3-body correlations of neighboring constituent atoms, and an optimized chemical representation of interatomic bonds in the crystal graphs. We demonstrate the accuracy of the improved framework in two distinct illustrations: First, when trained/validated on 180,000/20,000 density functional theory (DFT) calculated thermodynamic stability entries taken from the Open Quantum Materials Database (OQMD) and evaluated on a separate test set of 230,000 entries, iCGCNN achieves a predictive accuracy that is significantly improved, i.e., 20% higher than that of the original CGCNN. Second, when used to assist high-throughput search for materials in the ThCr2Si2 structure-type, iCGCNN exhibited a success rate of 31% which is 310 times higher than an undirected high-throughput search and 2.4 times higher than that of the original CGCNN. Using both CGCNN and iCGCNN, we screened 132,600 compounds with elemental decorations of the ThCr2Si2 prototype crystal structure and identified a total of 97 new unique stable compounds by performing 757 DFT calculations, accelerating the computational time of the high-throughput search by a factor of 130. Our results suggest that the iCGCNN can be used to accelerate high-throughput discoveries of new materials by quickly and accurately identifying crystalline compounds with properties of interest.