Leakage-Aware Bandgap Prediction on the JARVIS-DFT Dataset: A Phase-Wise Feature Analysis
Gaurav Kumar Sharma
TL;DR
This work addresses the problem of feature leakage in ML bandgap prediction by constructing a leakage-free subset of the JARVIS-DFT data and evaluating a three-phase feature framework. It combines careful data curation, a hierarchical feature expansion, and SHAP-based interpretability to assess how descriptor complexity affects accuracy, finding that $R^2$ saturates around $0.88$–$0.90$ despite richer feature spaces. The principal contribution is the leakage-controlled dataset and the baseline performance metrics, plus a robust finding that dielectric tensor features dominate predictions across phases. The practical impact is a more reliable framework for leakage-aware bandgap regression, guiding future work toward larger, diverse datasets and potentially deep learning approaches for further gains while maintaining interpretability.
Abstract
In this study, we perform a systematic analysis of the JARVIS-DFT bandgap dataset and identify and remove descriptors that may inadvertently encode band-structure information, such as effective masses. This process yields a curated, leakage-controlled subset of 2280 materials. Using this dataset, a three-phase modeling framework is implemented that incrementally incorporates basic physical descriptors, engineered features, and compositional attributes. The results show that tree-based models achieve R2 values of approximately 0.88 to 0.90 across all phases, indicating that expanding the descriptor space does not substantially improve predictive accuracy when leakage is controlled. SHAP analysis consistently identifies the dielectric tensor components as the dominant contributors. This work provides a curated dataset and baseline performance metrics for future leakage-aware bandgap prediction studies.
