Logo image
Predicting Gibbs free energy functions of inorganic compounds using machine learning
Thesis   Open access

Predicting Gibbs free energy functions of inorganic compounds using machine learning

Tran Quang Thai
Master of Science (M.S.), Drexel University
Jun 2023
DOI:
https://doi.org/10.17918/00001776
pdf
Thai_Tran_20233.62 MBDownloadView

Abstract

Gibbs' free energy Inorganic compounds Machine Learning
The goal of this thesis is to develop a machine learning model that can accurately predict the coefficients of the Gibbs free energy function for stoichiometric inorganic compounds. The model relies on a set of physical descriptors readily available from an established materials database of 0K density function theory (DFT) calculations (i.e., the Materials Project database). Knowing the Gibbs free energy of the phases in a system as a function of temperature, pressure, and chemical compositions provides the basis to predict the thermodynamic stability of the phases and the associated phase equilibrium and phase diagrams. However, obtaining Gibbs free energy data for many solid stoichiometric compound phases across a wide temperature range is challenging due to the high experimental or computational demands. In this thesis, we develop a machine learning model to predict the Gibbs free energy functions for 155 different solid compounds phases. These compounds belong to various categories, including intermetallic compounds, binary oxides, and ternary oxides, and the model covers the temperature range from 300K up to the decomposition temperature of each compound. The development process employs the random forest algorithm, combined with a hyper-parameter optimization method using random search and three-fold cross-validation. To train and evaluate the model, we utilize data from the SSUB6 database, which provides Gibbs free energy functions derived from high-fidelity experimental thermochemical data. 26 physical descriptors are extracted from the Materials Project database to be considered as features in the machine learning model. This thesis also provides a framework for future work on expanding the coverage to the high-temperature stable phases and other classes of compounds (e.g., carbides, nitrides, etc.), making the model more robust.

Metrics

1278 File views/ downloads
57 Record Views

Details

Logo image