Carlo M. Grammaccioli : EMU 4 Energy Modelling in Minerals

Carlo M. Grammaccioli : EMU 4 Energy Modelling in Minerals

From the Introduction

The present book shows the arguments which have been considered in the EMU School (No.4), dealing with Energy Modelling in Minerals; these arguments have been selected in order to provide examples of application of the most advanced theories to several cases. It should be pointed out that although the ultimate solution of our problems should involve "ab initio" quantum-mechanical calculations, at present such sophisticated procedures are far from being routine. Therefore, although "ab initio" approaches will play an ever-increasing role in the future and some important and most recent examples of such approaches are illustrated here, the greatest part of the contributions is dealing with empirical atom-atom calculations.

Remarkably enough, such "semi-empirical" applications are often quite successful, providing excellent (or comparatively excellent) results in spite of their more or less approximate nature. It often happens that the methods here illustrated are some steps ahead of the current level of empirical treatment, thereby indicating a possible way of improvement by figuring out routines to be adopted in practice. If some methods seem to be too speculative to be actually usable, here they also are shown, in view of their possible discussion, or just to indicate a way to obtain promising developments. Among the descriptions of practical methods and results, some purely theoretical arguments have been inserted; these arguments - although abstract - according to our opinion are fundamental for earth scientists.

Owing to the present status of the art, in a number of arguments there is no unique opinion with respect to their theoretical treatment as it is explained by different authors. Instead of having all of them discarded except the one which looks to be the most appropriate to the Editor (who might sometimes be personally involved in the question), most of such controversial points have been left just as they are, in the original draft of their advocates. Accordingly, the reader might find some discrepancies between some articles and others, which may lead to some obscurity; there are, however, several good reasons in favour of our behaviour. First of all, with a few exceptions we apologize about, our attention in inviting the contributors has been extended to all the principal authors in the world, with no limitation to a group of particular friends; moreover, the presence of different opinions in the context might give rise to interesting debates and critical objections; a further point is that the validity of the different treatments is shown per se by either the level of the theory and most of all by the agreement with the corresponding experimental data. Since we have to do with an advanced school, and in line with what should be a scientific procedure, it is important to provide the user with the possibility of choosing what seems to be the most appropriate method among a number of selected possibilities, rather than yielding to the assertion that something is indeed the ultimate and unquestionable "truth".

Carlo Maria Grammaccioli, Milan, December 2002

Contents of Volume 4

• Chapter 1. Introduction by Carlo M. GRAMACCIOLI
• Chapter 2. Thermochemistry, energetic modelling, and systematics by Alexandra NAVROTSKY
• Chapter 3. Computer simulation of structure and properties of minerals by minimisation of atomisation energy by Vadim S. URUSOV
• Chapter 4. Reverse Monte Carlo methods by Martin T. DOVE
• Chapter 5. Ab initio theory of phase transitions and thermoelasticity of minerals by Artem R. OGANOV, John P. BRODHOLT and G. David PRICE
• • Part I: A brief geophysical introduction
  • Part II: Thermoelastic properties
  • Part III: Phase transitions
  • Part IV: Simulation methods
  • Part V: Examples from recent studies
• Chapter 6. Vibrational symmetry and spectroscopy by Alessandro PAVESE
• Chapter 7. Quantum-mechanical simulations of the high-pressure behaviour of crystals by Michele CATTI
• Chapter 8. Lattice dynamics, inelastic neutron scattering and thermodynamic properties of minerals by Narayani CHOUDHURY, Samrath Lal CHAPLOT, Subrata GHOSE, Mala N. RAO and Ranjan MITTAL
• • I. Introduction
  • II. Lattice dynamics
  • III. Inelastic neutron scattering technique
  • IV. vThermodynamic propertiesv
• Chapter 9. Lattice dynamics: Theory and application to minerals by Carlo M. GRAMACCIOLI
• Chapter 10. Diffusion kinetics in minerals: Principles and applications to tecto-metamorphic processes by Jibamitra GANGULY
• Chapter 11. Microscopic strain, macroscopic strain and the thermodynamics of phase transitions in minerals by Michael A. CARPENTER
• Chapter 12. Microscopic-macroscopic relationships in silicates: Examples from IR and Raman spectroscopy and heat capacity measurements by Charles A. GEIGER and Boris A. KOLESOV
• Chapter 13. Atomic displacement parameters from diffraction studies: The experimental evidence by Gilberto ARTIOLI