Chem. Mater., 30, 4031-4038 (2018) [pdf]

Machine-Learning Assisted Accurate Band Gap Predictions of Functionalized MXene

Arunkumar Chitteth Rajan, Abanish Mishra, Swanti Satsangi, Rishabh Vaish, Hiroshi Mizuseki, Kwang-Ryeol Lee, Abhishek K. Singh

MXene are two-dimensional (2D) transition metal carbides and nitrides, and are invariably metallic in pristine form. While spontaneous passivation of their reactive bare surfaces lends unprecedented functionalities, consequent many-folds increase in number of possible functionalized MXene makes their characterization difficult. Here, we study the electronic properties of this vast class of materials by accurately estimating the band gaps using statistical learning. Using easily available properties of the MXene, namely boiling and melting points, atomic radii, phases, bond lengths etc. as input features, models were developed using kernel ridge (KRR), support vector (SVR), Gaussian Process (GPR) and bootstrap aggregating regression algorithms. Among these, the GPR model predicts the band gap with lowest root-mean-squared error (rmse) of 0.14 eV, within seconds. Most importantly, these models do not involve the Perdew-BurkeErnzerhof (PBE) band gap as a feature. Our results demonstrate that machine learning models can bypass band gap underestimation problem of local and semi-local functionals used in density functional theory (DFT) calculations, without subsequent correction using time-consuming GW approach.