8 - Electronic Structure

Abstract

This chapter focuses on the quantum mechanical (QM) studies of silicate and oxide systems. The chapter deals with various theoretical models and discusses the computational realization of these models in the context of modern computer technology. The plane waves (PW)- local density approximation (LDA) and linear combination of atomic orbitals (LCAO)-Hartree–Fock (HF) theory have been extensively used on silicate and oxide materials and suffice to exemplify the effects of a varying basis set and one electron potential in these systems. The applications of these techniques focus on materials with complex geometrical structures (silicates and simple oxides) where the problems associated with the application of the theory are confined to the scale of the system. Recent attempts to compute the ground state properties of materials with complex electronic structure, mostly transition metal oxides, are reviewed in the chapter. Periodic LCAO-HF calculations are used to examine the electronic structure and related properties of a number of silaceous structures such as zeolite cages and clay-like minerals. The computational cost of such studies restricts structural optimization to calculations using minimal basis sets.