Quantum geochemistry

The early 1970s also saw the birth of a new subfield on the borderline of mineralogy, chemistry, and solid-state physics, the field we have called quantum geochemistry (although the basis for such a field was laid by researchers in the 1950s and 1960s, as we have described). 

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A more detailed account of the Schrodinger equation can be found in physical chemistry textbooks such as those of Hinshelwood (1951) and Atkins (1978), or in more specialized texts such as that of Hirschfelder et al. (1954). An excellent review of the applications of quantum mechanics to geochemistry has recently been proposed by Tossell and Vaughan (1992). 

Tossell J. A. and Vaughan D. J. (1992). Theoretical Geochemistry Application of Quantum Mechanics in the Earth and Mineral Sciences. New York-Oxford Oxford University Press. 

The divide between these two end-members can be fuzzy in practice (Figure 5.2). Development of hybrid codes that employ each method on different components of a model has been a great advance in modeling larger-scale systems.37 Termed QM/MM for quantum mechanics/molecular mechanics, this approach will likely enjoy widespread utilization and success in fields such as soil science, environmental chemistry, and geochemistry due to the nature and complexity of reactions in these fields. Furthermore, as computers become more powerful and software becomes more advanced, it becomes feasible to perform molecular simulations using quantum... 

Theoretical Geochemistry Applications of Quantum Mechanics in the Earth and Mineral Sciences... 

In addition to the contributions to understanding the Earth s interior from geophysical evidence and the geochemistry of solar system materials, and from very high-pressure experiments, an important contribution comes from attempts to calculate the effects of pressure on crystal and electronic structures of appropriate materials using quantum-mechanical methods. Some examples of this approach will now be considered, with reference to the phases thought likely to dominate the interior of the Earth. 

In this final chapter, an attempt is made to provide an overview of the capabilities of quantum-mechanical methods at the present time, and to highlight the needs for future development and possible future applications of these methods, particularly in areas related to mineral structures, energetics, and spectroscopy. There is also a brief account of some new areas of application, specific directions for future research, and possible developments in the perception and use of quantum-mechanical approaches. The book ends with an epilog on the overall role of theoretical geochemistry in the earth and environmental sciences. 

Theoretical geochemistry applications of quantum mechanics in the earth and mineral sciences / John A. Tossell, David J Vaughan, p. cm. Includes bibliographical references and index. 

It is the thesis of this book that further major advances in geochemistry, particularly in understanding the rules that govern the ways in which elements come together to form minerals and rocks, require application of the theories of quantum mechanics. This is particularly the case in gaining further knowledge of the geochemistry of the interior of the Earth. 

Quantum mechanical calculations on clay minerals are essential in computational geochemistry today. They can serve to provide the interparticle potential for the clay-water-adsorbate system for MC and/or MD simulations. They can also determine the clay structure without experimental parameters. To this end, the recent development in first-principles calculations using density functional theory (DFT) will be discussed and compared with semiempirical ab initio and Hartree-Fock methods. Recent success in determining 2 1 clay mineral equilibrium structures (both neutral and charged clays) will be discussed and compared with available experimental data. The most challenging and desired simulations... 

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