Hydrogen is a ubiquitous impurity in diamond but in contrast to other group IV materials the microscopic structure adopted in bulk material has largely remained elusive. It has therefore been the role of modelling to predict the properties of H in bulk diamond, as well as the interactions with impurities and other defects. Presented here is an account of the current theoretical understanding of hydrogen in diamond.
Contents1. Introduction 552 2. Theoretical approaches 554 2.1. Hartree-Fock based methods 554 2.2. Density functional methods 555 2.3. Tight-binding approaches 555 2.4. Basis sets and Brillouin zone sampling 556 2.5. Classical versus quantum mechanical treatment of the H atoms 556 2.6. Summary 556 2.7. Calculation of experimental observables 557 3. Muonium and interstitial hydrogen 561 3.1. Muonium hyperfine coupling constants 563 3.2. Electrical activity of isolated hydrogen 564 3.3. Vibrational modes of interstitial H 565 3.4. Diffusion of interstitial hydrogen 565 3.5. Solubility of bond-centred hydrogen 567 3.6. Hydrogen in near-surface region 567 4. Di-hydrogen aggregates 568 5. Hydrogenated lattice vacancies 569