https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/202086/1/j.scriptamat.2015.07.021.pdf

First principles phonon calculations in materials science

Phonon plays essential roles in dynamical behaviors and thermal properties, which are central topics in fundamental issues of materials science. The importance of first principles phonon calculations cannot be overly emphasized. Phonopy is an open source code for such calculations launched by the present authors, which has been world-widely used. Here we demonstrate phonon properties with fundamental equations and show examples how the phonon calculations are applied in materials science.

1. Introduction 2. Nuclear scattering - basic theory 3. Nuclear scattering by crystals 4. Correlation functions in nuclear scattering 5. Scattering by liquids 6. Neutron optics 7. Magnetic scattering - basic theory 8. Scattering from magnetically ordered crystals 9. Polarisation analysis Appendices Solutions to examples Index.

https://assets.cambridge.org/97811076/44069/frontmatter/9781107644069_frontmatter.pdf

Introduction to the Theory of Thermal Neutron Scattering

We describe the work of the European project QUASI (Quantum Simulation in Industry, project EP25047) which has sought to develop a flexible QM/MM scheme and to apply it to a range of industrial problems. A number of QM/MM approaches were implemented within the computational chemistry scripting system, ChemShell, which provides the framework for deploying a variety of independent program packages. This software was applied in several large-scale QM/MM studies which addressed the catalytic decomposition of N 2 O by Cu-containing zeolites, the methanol synthesis reaction catalysed by Cu clusters supported on ZnO surfaces, and the modelling of enzyme structure and reactivity.

QUASI: A general purpose implementation of the QM/MM approach and its application to problems in catalysis

We present a unified theory for wave-packet dynamics of electrons in crystals subject to perturbations varying slowly in space and time. We derive the wave-packet energy up to the first-order gradient correction and obtain all kinds of Berry phase terms for the semiclassical dynamics and the quantization rule. For electromagnetic perturbations, we recover the orbital magnetization energy and the anomalous velocity purely within a single-band picture without invoking interband couplings. For deformations in crystals, besides a deformation potential, we obtain a Berry-phase term in the Lagrangian due to lattice tracking, which gives rise to new terms in the expressions for the wave-packet velocity and the semiclassical force. For multiple-valued displacement fields surrounding dislocations, this term manifests as a Berry phase, which we show to be proportional to the Burgers vector around each dislocation.

Wave-packet dynamics in slowly perturbed crystals: Gradient corrections and Berry-phase effects

Dynamics of perfect crystals

This paper offers (in two parts) a broad overview of recent developments concerning the use of curved space concepts in amorphous structures. Keeping particularly in mind nonspecialist readers, expository background material is included, wherever appropriate. Part I deals essentially with geometrical modelling, and starts with a brief recapitualtion of the famous model-building exercise due to Bernal. We then discuss the Kleman-Sadoc prescription for realizing amorphous structures as mappings of spherical polytopes (the four-dimensional analogue of spherical polyhedra) onto Euclidean space. Such an approach has not only provided a fast and convenient algorithm, but more importantly, has focused attention on the line defects (disclinations) in amorphous structures. As a result, one is now able to relate these disclinations to the Frank-Kasper lines present in complex alloy structures. In turn, this has led to a qualitative scenario for the transformation of the liquid during a cool-down, into the ...

Curved space and amorphous structures part I Geometric models

C.V. Raman is best known to the scientific community for the effect which bears his name and other derivative terms. He was also a Nobel Prize winner in Physics. Little else is generally known about his life. Fiercely independent and critical of Government policies, Raman was often misunderstood and maligned; however his commitment to science and to its growth in India never wavered. This account deals with all these aspects of Raman's life and work and places them in their historical and cultural context. Numerous quotations help capture the mood and excitement of those times. The book is not only a lively biography of a colourful personality, but also required reading for anyone with a serious interest in and concern for Indian science.

Journey into Light: Life and Science of C.V. Raman

In Part I we discussed how amorphous structures can be regarded as mappings from curved spaces, and how such mappings provided us a perspective on the line defects of topological origin that possibly exist in amorphous materials. The existence of such defects also permits us to speculate that the liquid, crystalline and amorphous states differ largely in the spatial organization and the kinetics of such defects. Gauge theories offer a means of quantifying such notions, and Part II reviews recent attempts in this direction. We commence with some mathematical preliminaries concerning differential geometry, and then explain what is meant by a gauge theory by considering a few examples from condensed matter physics. We then review the recent works of Rivier and Duffy, of Nelson and co-workers and of Sethna concerning a possible gauge/gauge-type theory for glass. We conclude by making a broad assessment of the progress thus far and of the territory that lies beyond. “If Nature leads us to mathematical...

Curved space and amorphous structures part II. Gauge theories

This chapter is concerned with the emergence of order out of disorder, and specifically with symmetry breaking in phase transitions in the framework of the Landau theory [3.1, 2].

Ganesan Venkataraman

Papers

Dynamics of perfect crystals

Curved space and amorphous structures part I Geometric models

Journey into Light: Life and Science of C.V. Raman

Curved space and amorphous structures part II. Gauge theories

Order Out of Disorder