Abstract

• Abstract
• Modelling complex structures

• Introduction
• Pressure Effects in Semiconductors
• Molecular Dynamics

• Modelling the Interactions
• The Molecular Dynamics Method
• Layout of Thesis
• First Principles Molecular Dynamics

• Introduction
• Earlier Approximations
• Density Functional Theory
• Exchange, Correlation and the Local Density Approximation
• Bloch's Theorem and Plane Wave Basis Sets
• k-point Sampling

• Discretisation of k-space
• Special k-point Sets
• Charge Symmeterisation
• Ion-Electron Interactions

• The Pseudopotential Approximation
• Norm Conserving Pseudopotentials
• Kleinman-Bylander Pseudopotentials
• The Car-Parrinello Method

• Car-Parrinello Lagrangian
• Orthonormality
• More Efficient Methods: Conjugate Gradients and Preconditioning
• Molecular Dynamics
• Metals
• Summary of MD Codes
• Complex Phases: Ab Initio Treatment

• Introduction
• Total Energy Calculations
• Internal Structure of BC8 and ST12
• Results on Structure

• Silicon and Germanium
• Carbon
• The Structural Response to Compression
• Constant Volume MD
• Band Structures
• Nature of Bonding
• Trends
• III-IV Semiconductor Calculations

• Introduction
• The SC16 Structure
• Total Energy Calculations
• Molecular dynamics
• Ionicity
• Electronic Band Structure
• Conclusions
• Complex Structures: Empirical Treatment

• Introduction
• Lattice Dynamics
• The Empirical Potential
• Effect of Pressure on Structure
• Phonon Dispersion
• Free Energies
• Conclusions
• The Lowest Energy Silicon Surface?

• Introduction
• Surfaces of the Diamond Structure
• Ab Initio Modeling of Surfaces
• Construction of Si-BC8 Surface
• Adatom Reconstructed Surfaces
• Discussion and Conclusions
• Point Defects In Silicon

• Introduction
• Ab Initio Calculations

• Vacancy
• Self Interstitials
• Empirical Calculations

• Structural and Vibrational Calculations
• Free Energy and Entropy
• Effect on Elasticity
• Conclusions
• Amorphous Carbon and Silicon

• Introduction
• Modelling Amorphous Materials
• Structural Details

• Silicon
• Carbon
• Electronic properties
• Discussion
• References
• About this document ...