1 Introduction: Gas Source Growth
 1.1 Materials modelling
 1.2 Experiments and theory
 1.3 Interpreting STM images
 1.4 Kinetics
 1.5 Overview
2 Theoretical Techniques
 2.1 General ideas
  2.1.1 The Born-Oppenheimer approximation
  2.1.2 The Hellmann-Feynman theorem
  2.1.3 Representing an infinite solid
  2.1.4 Modelling Transitions and Reactions
 2.2 Density functional theory
  2.2.1 Approximating the exchange and correlation energy
  2.2.2 Pseudopotentials
  2.2.3 A plane wave code: CASTEP
 2.3 Tight binding
 2.4 Linear scaling tight binding methods
 2.5 The density matrix method
 2.6 Recursion methods
  2.6.1 The global density of states method
  2.6.2 The Fermi operator expansion method
  2.6.3 The bond order potential method
3 Technical Issues: Linear Scaling and Parameterisations
 3.1 A comparison of linear scaling tight binding methods
  3.1.1 Total energies and vacancy formation energies
  3.1.2 Forces and efficiency
  3.1.3 Titanium: moments’ revenge !
 3.2 Tight binding parameterisations
 3.3 Si-Si bonding
 3.4 Si-H bonding
  3.4.1 Tests of the parameterisations
 3.5 Si-Bi and Bi-Bi bonding
4 The Clean Silicon(001) Surface: Defects and Steps
 4.1 The perfect surface
 4.2 Electronic enhancement and strained bonding
 4.3 Step energies and structures
  4.3.1 Terrace sizes for rebonded and unbonded steps
  4.3.2 Step edge enhancement
  4.3.3 Kink structures and energies for A- and B-type steps
5 Bismuth on Si(001)
 5.1 Stable structures for bismuth
 5.2 The straightest lines in the world ?
 5.3 A mysterious reconstruction
6 Hydrogen on Si(001)
 6.1 Hydrogen diffusing on Si(001)
 6.2 STM results and phenomenological modelling
 6.3 Atomistic modelling of single atom diffusion
  6.3.1 DFT calculations
  6.3.2 TB calculations
 6.4 Diffusion on the saturated surface
 6.5 Behaviour of hydrogen at steps and defects
  6.5.1 Saturation of steps and relation to growth
  6.5.2 Hydrogen at defects: nano-mirrors
7 Growth of Si(001) from disilane
 7.1 SiH₂ fragments
 7.2 SiH₂ diffusion
 7.3 Monohydride dimer formation
 7.4 Rotation and dehydrogenation of ad-dimers
  7.4.1 Rotation of the clean dimer
  7.4.2 Rotation of the hydrogenated dimer
  7.4.3 A possible dehydrogenation mechanism
 7.5 Dimer diffusion along the trench between dimer rows
 7.6 A new feature: the square
  7.6.1 Identification
  7.6.2 Formation and Transformation
 7.7 Nucleation of dimer strings from the square
 7.8 The path from adsorbed disilane fragments to dimer strings
 7.9 Anti-phase boundaries
8 Conclusion
 8.1 Tight Binding is Good Enough
 8.2 Every theorist needs an experimentalist
 8.3 Now we can do germanium
References