Preface

Molecular dynamics (MD) simulations have played increasing roles in our understanding of physical and chemical processes of complex systems and in advancing science and technology. Over the past forty years, MD simulations have made great progress from developing sophisticated theories for treating complex systems to broadening applications to a wide range of scientific and technological fields. The chapters of *Molecular Dynamics* are a reflection of the most recent progress in the field of MD simulations.

This is the first book of *Molecular Dynamics* which focuses on the theoretical developments and the applications in nanotechnology and energy. This book is divided into five parts. The first part deals with the development of molecular dynamics theory. Komeiji et al. summarize, in Chapter 1, the advances made in fragment molecular orbital based molecular dynamics, which is the *ab inito* molecular dynamics simulations, to treat large molecular systems with solvent molecules being treated explicitly. In Chapter 2, Wang & Hudson present a new meta-molecular dynamics method, i.e. beyond the conventional MD simulations, that allows monitoring the change of electronic state of the system during the dynamical process. Fukuda & Queyroy discuss in Chapter 3 two numerical techniques, i.e. phase space time-invariant function and numerical integrator, to enhance the MD performance. In Chapter 4, Rosas-García & Sáenz-Tavera provide a summary of MD methods to perform a configurational search of clusters of less than 100 atoms. In Chapter 5, Termentzidis & Merabia describe MD simulations in the calculation of thermal transport properties of nanomaterils.

The second part consists of three chapters that describe MD theory beyond a classical treatment. In Chapter 6, Wong describes a practical ab inito path-integral method, denoted as method, for macromolecules. Chapters 7 and 8, by Rampho and Togashi & Katō, respectively, deal with the asymmetric molecular dynamics simulations of nuclear structures.

Part III is on nanoparticles. In Chapter 9, Liu et al. provide a detailed description of MD simulations to study liquid metal clusters consisting of up to 106 atoms. In Chapter 10, Çiftci & Özgen provide a MD study of Au clusters on the melting, glass formation, and crystallization processes. Lim provides a MD study of gelation of magnetic nanoparticles in Chapter 11. Chapter 12 by Gutiérrez et al. provides a MD simulation of a nanoparticle colliding inelastically with a solid surface.

The fourth part is about diffusion of gas molecules in solid, an important research area related to gas storage, gas separation, catalysis, and biomedical applications. In Chapter 13, Keskin describes MD simulations of the gas diffusion in molecular organic framework (MOF). In Chapter 14, Pastukhov et al. provide the MD results on the H2 dynamics on various solid surfaces. In Chapter 15, Tokumasu provides a summary of MD results on H2 dissociation on Pt(111). In Chapter 16, Mu & Li discuss MD simulation of the adsorption and diffusion of polydimethylsiloxane (PDMS) on a Si(111) surface.

In the last part of the book, ionic conductivity in solid oxides is discussed. Solid oxides are especially important materials in the field of energy, including the development of fuel cells and batteries. In Chapter 17, Lau & Dunlap describe the dynamics of O2- in Y2O3 and in Y2O3 doped crystal and amorphous ZrYO. Khoo & Dissado provide a study of the mechanism of Na+ conductivity in hollandites in Chapter 18. The last chapter of this part deals with the ion solvation in methanol/water mixture. Hawlicka and Rybicki summarize the Mg2+, Ca2+, and Cl solvation in the liquid mixture and I hope the readers can find connections between the liquid and solid ionic conductivities.

With strenuous and continuing efforts, a greater impact of MD simulations will be made on understanding various processes and on advancing many scientific and technological areas in the foreseeable future.

In closing I would like to thank all the authors taking primary responsibility to ensure the accuracy of the contents covered in their respective chapters. I also want to thank my publishing process manager Ms. Daria Nahtigal for her diligent work and for keeping the book publishing progress in check.

> **Lichang Wang**  Department of Chemistry and Biochemistry Southern Illinois University Carbondale USA
