Computational materials chemistry: from polymer precursors to ceramics and high-pressure materials

Abstract

With advances in computing power, the field of computational chemistry has flourished. Using current computational resources, atomistic simulations of billion atoms and trillions of atoms have been performed. Computational techniques can be used to support experimental investigations into new materials as well as independently predict the existence of new materials. Furthermore, computational techniques are becoming instrumental in investigations. This work is split into two parts. Part I focuses on high-pressure and materials chemistry. We investigate the cristobalite-rutile transformation for SiO2, GeO2, and TiO2, and predict conditions at which cristobalite-GeO2 and cristobalite-TiO2 may be synthesized (Chapter 1), we provide supporting calculations for the discovery of two ternary compounds, Sn2N2O (Chapter 2) and Si-Ti-N (Chapter 3), synthesized at high pressure, and we investigate the work of adhesion in compound graphene-SiO2/Si2CO2 systems (Chapter 4). Part II is focused on studying amorphous ceramics, including polymer-derived ceramics with classical methods. We calculate elastic properties of SiCO ceramics and determine the impact of free carbon content, density, and free carbon morphology (Chapter 1), we develop a new method to quantify the extent of the free carbon morphology in large atomistic systems (Chapter 2), and we develop a new parametrization of the reactive force field ReaxFF for simulations of the polymer-to-ceramic conversion process used to synthesize silicon carbonitride from polysilazanes (Chapter 3).