CONTENTS -- 1. INTRODUCTION -- 1.1 Historical perspective-ionic and atomistic approaches -- 1.2 Crystal-field theory and the geochemistry of the transition metals -- 1.3 Quantum chemistry -- 1.4 Solid-state quantum physics (band theory and related approaches) -- 1.5 Quantum geochemistry -- 1.6 Models and methods -- 2. EXPERIMENTAL METHODS -- 2.1 Diffraction effects -- 2.1.1 X-ray diffraction -- 2.1.2 Neutron diffraction -- 2.1.3 Electron diffraction and associated phenomena -- 2.2 Electron and x-ray spectroscopy -- 2.2.1 Photoelectron spectroscopy (and Auger electron spectroscopy) -- 2.2.2 X-ray emission spectroscopy -- 2.2.3 X-ray absorption spectroscopy (including EXAFS and XANES) -- 2.3 Optical (uv-visible-near-ir) spectroscopy -- 2.3.1 Electronic (optical) absorption spectroscopy -- 2.3.2 Reflectance (diffuse and specular) spectroscopy -- 2.4 Vibrational spectroscopy -- 2.4.1 Theoretical basis -- 2.4.2 Infrared spectroscopy -- 2.4.3 Raman spectroscopy -- 2.4.4 Reporting of data -- 2.5 Nuclear spectroscopy -- 2.5.1 Nuclear quadrupole resonance -- 2.5.2 Nuclear magnetic resonance -- 2.5.3 The Mössbauer effect -- 2.6 Other methods -- 2.6.1 Electron spin resonance -- 2.7 Concluding remarks -- 3. THEORETICAL METHODS -- 3.1 Elements of quantum mechanics -- 3.2 Details of Hartree-Fock-Roothaan calculations: Choice of basis set -- 3.2.1 Minimum basis sets -- 3.2.2 Extended basis sets: Double-ζ bases -- 3.2.3 Extended basis sets: Polarized bases -- 3.2.4 Extended basis sets: Other approaches -- 3.2.5 Basis set and calculated properties -- 3.3 Improvements on the Hartree-Fock wave function -- 3.4 Dependence of computation time on basis-set size (and property calculated) for Hartree-Fock-Roothaan and configuration-interaction calculations -- 3.5 Prediction of properties other than equilibrium geometries from Hartree-Fock-Roothaan calculations.

3.6 Evaluation of spectral and other experimental parameters using Hartree-Fock-Roothaan calculations -- 3.7 Approximate Hartree-Fock methods -- 3.8 Hartree-Fock band-structure calculations -- 3.9 Elements of density-functional theory -- 3.10 The multiple-scattering or scattered-wave X-α method -- 3.11 Density-functional band theory -- 3.12 Theoretical ionic models-the modified electron-gas approach -- 3.13 Simulation methods -- 3.14 Combined local-density-functional molecular dynamics approach -- 3.15 Relationships between localized and delocalized approaches -- 3.15.1 Orbital and band energies -- 3.15.2 Incorporation of external atoms of the solid into cluster calculations -- 3.16 Concluding remarks on different theoretical approaches -- 4. APPLICATION OF QUANTUM-MECHANICAL METHODS TO SIMPLE INORGANIC "MOLECULES" OF RELEVANCE TO MINERALOGY, AND TO OXIDE MINERALS -- 4.1 The inorganic molecules SiO, SiO[sub(2)], Si[sub(2)]O[sub(2)], and Si[sub(3)]O[sub(3)] -- 4.2 The SiF[sub(4)] molecule -- 4.2.1 Geometric structure of SiF[sub(4)] -- 4.2.2 Electronic structure of SiF[sub(4)] - electron spectroscopy -- 4.2.3 Electronic structure of SiF[sub(4)] - x-ray-absorption spectra -- 4.2.4 Electronic structure of SiF[sub(4)] - [sup(29)]Si NMR spectra -- 4.3 Major oxide minerals -- 4.3.1 MgO (periclase) -- 4.3.2 Al[sub(2)]O[sub(3)] (corundum) -- 4.3.3 SiO[sub(2)] [silica polymorphs -- also Si(OH)[sub(4)], SiO[sub(4)] [sup(-4)], (SiH[sub(3)])[sub(2)]O, and (OH)[sub(3)]SiOSi(OH)[sub(3)]] -- 4.4 Transition-metal oxides -- 4.4.1 Titanium oxides -- 4.4.2 Manganese oxides -- 4.4.3 Iron oxides (and hydroxides) -- 4.4.4 Complex oxides -- 4.4.5 Band theory and the transition-metal monoxides -- 4.5 Calculation of Mössbauer parameters in iron oxides (and other iron compounds) -- 5. APPLICATIONS TO SILICATE, CARBONATE, AND BORATE MINERALS AND RELATED SPECIES.

5.1 Introduction -- 5.2 Silicates -- 5.2.1 Olivines: Geometric structures -- 5.2.2 Olivines: Electronic structures -- 5.2.3 Element distributions and solid solutions in olivines -- 5.2.4 Structure and stability of silicates of intermediate polymerization -- 5.2.5 Electronic structures of silicates other than olivines and SiO[sub(2)] -- 5.3 Carbonates -- 5.3.1 Carbonates: Geometric structures -- 5.3.2 Carbonates: Electronic structures and properties -- 5.4 Borates -- 5.4.1 B[sub(2)]O[sub(3)] and the borates: Geometric structures -- 5.4.2 B[sub(2)]O[sub(3)] and the borates: Spectra and electronic structures -- 6. APPLICATION OF BONDING MODELS TO SULFIDE MINERALS -- 6.1 Introduction -- 6.2 Sphalerite, würtzite, and related phases [ZnS, CdS, HgS, (Zn,Fe)S] -- 6.3 Galena (PbS) and the isostructural selenide and telluride minerals (PbSe, PbTe) -- 6.4 Pyrite (FeS[sub(2)]), pyrrhotite (Fe[sub(1-x)]S), and related phases (CoS[sub(2)], NiS[sub(2)], CuS[sub(2)], ZnS[sub(2)] -- CoS, NiS) -- 6.5 Marcasite (FeS[sub(2)]), arsenopyrite (FeAsS), loellingite (FeAs[sub(2)]), and related minerals -- 6.6 Copper, copper-iron, and related sulfides (Cu[sub(2)]S, CuS, CuFeS[sub(2)], Cu[sub(5)]FeS[sub(4)], Ag[sub(2)]S) -- 6.7 The thiospinels [Co[sub(3)]S[sub(4)], CuCo[sub(2)]S[sub(4)], (Co,Ni)[sub(3)]S[sub(4)], Ni[sub(3)]S[sub(4)], FeNi[sub(2)]S[sub(4)], FeCr[sub(2)]S[sub(4)]] -- 6.8 Other (including complex) sulfides [MoS[sub(2)], Co[sub(9)]S[sub(8)], (Ni,Fe)[sub(9)]S[sub(8)], Cu[sub(12)]Sb[sub(4)]S[sub(13)], etc.] -- 6.9 Concluding remarks -- 7. APPLICATIONS IN MINERAL PHYSICS AND CHEMISTRY -- 7.1 Structure, bonding, and stereochemistry -- 7.1.1 Covalency and ionicity in solids from calculation and experiment -- 7.1.2 Calculation of geometric structures and their (phase) relations: The example of the SiO[sub(2)] polymorphs -- 7.1.3 Pauling's rules reinterpreted.

7.1.4 Qualitative molecular-orbital theory and its applications -- 7.2 Minerals at elevated pressures and the interior of the Earth -- 7.2.1 Olivine and Mg[sub(2)]SiO[sub(4)] spinel -- 7.2.2 MgSiO[sub(3)]and CaSiO[sub(3)] perovskite -- 7.2.3 Simple oxides, structural and electronic phase transitions -- 7.2.4 Iron (and Fe-rich alloys) at core pressures -- 7.3 Industrial mineral materials -- 7.3.1 Zeolites -- 7.3.2 Transition-metal sulfide catalysts -- 7.4 Concluding remarks -- 8. APPLICATIONS TO GEOCHEMICAL PROBLEMS -- 8.1 The nature of melts, glasses, and crystal-melt equilibria -- 8.1.1 Silica glass and melt -- 8.1.2 Glasses and melts of more complex compositions -- 8.1.3 Crystal-melt equilibria -- 8.2 Solution species -- 8.2.1 Quantum-mechanical studies of water and aqueous (ionic) solutions -- 8.2.2 Aqueous metal complexes, hydrothermal solutions, and hydrothermal ore deposits -- 8.2.3 Theoretical studies on Zn chloride complexes in aqueous solution -- 8.3 Mineral surfaces -- 8.3.1 The surface of MgO (periclase) -- 8.3.2 The surface of TiO[sub(2)] (rutile) -- 8.3.3 Oxide surface defects and the reactivity of surfaces -- 8.3.4 The surface of ZnS (sphalerite) -- 8.3.5 The surface of Cu[sub(5)]FeS[sub(4)] (bornite) and atmospheric tarnishing -- 8.3.6 Concluding remarks on surface studies -- 8.4 Geochemical distribution of the elements -- 8.4.1 The Goldschmidt classification: Ionic and orbital interpretations -- 8.4.2 Lithophile versus chalcophile behavior: The M-O versus the M-S bond -- 8.4.3 Geochemical coherence and geochemical differentiation -- 9. THE FUTURE -- 9.1 Capabilities of quantum-mechanical methods -- 9.2 Future areas of application in structures and energetics -- 9.3 Future applications in mineral spectroscopy -- 9.4 New areas of application -- 9.5 Research directions.

9.6 Epilog: Theoretical geochemistry and the Earth and environmental sciences -- APPENDIX A: Symbols, units, conversion factors, and constants -- APPENDIX B: Experimental methods for obtaining information on structure and bonding -- APPENDIX C: Quantum-mechanical (and related) calculational methods and terminology -- REFERENCES -- INDEX -- A -- B -- C -- D -- E -- F -- G -- H -- I -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- W -- X -- Z.