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Maggie Kingsland

Ferroelectrics are materials that have spontaneous polarization and this polarization is switch- able with the application of an electric field. Ferroelectric materials are an integral part of modern electronics. Therefore, being able to accurately predict their properties using computational meth- ods is paramount. Commonly used density functionals, such as generalized gradient approximation (GGA) and local density approximation (LDA), overestimate or underestimate the Curie temper- atures, respectively. In this project, we try to resolve these issues by testing new functionals (MN12-L, GAM, HLE17, SOGGA, etc.) on the prototypical ferroelectric materials lead titanate (PTO) and barium titanate (BTO). We investigate properties, such as polarization, energy differ- ence between the cubic and tetragonal states, and band gap energy, for both materials. We do not find a particular functional among those tested that better predicts all the properties of interest than the typical functionals. However, we indicate which functionals are better at predicting par- ticular properties than the typical functionals and is best at estimating these properties among the tested functionals.