Development Of Multi-Scale Computational Tools For The Study Of Interfaces

Abstract

Interfaces play a pivotal role in modern devices and applications. A proper understanding of them requires an approach that supplements the experimental studies with appropriate computational undertakings. Computational methodologies and tools play a major role in the enhancement of the understanding of existing as well as newly discovered technologies. Since a unified theory/software tool that describes all encompassing phenomena does not yet exist, a variety of models/tools that deals with various phenomena at a range of length and time scales need to be considered. This calls for the development of combined models that are computationally efficient and scientifically accurate to describe the length and time scales relevant to the processes in the systems of interest. This thesis describes the development and the implementation of such combined methods/tools for the simulation and analysis of a variety of interfacial systems. The first part of this thesis presents the development and implementation of efficient implicit solvation models to describe solid-liquid interfaces in the density-functional theory (DFT) framework and its implementation in the widely used DFT code Vienna Ab-initio Software Package (VASP). This is followed by the description of the development of an open-source highthroughput framework for the creation, screening, simulation, and analysis of interfacial systems. The high-throughput framework enables the creation of various interfacial structures such as solid/liquid interfaces, nanocrystal/ligands and heterostructure interfaces. The framework also enables the generation of input files for various DFT/MD softwares so that an in depth analysis of the screened interfaces at different length scales can be done if desired. The open-source tools developed as part of this work are made freely available and some have already become part of widely used scientific software packages such as the VASP DFT code.