Advances in nanoscale science show that the properties of many materials are dominated by internal structures. In molecular cases, such as window glass and proteins, these internal structures obviously have a network character. However, in many partly disordered electronic materials, almost all attempts at understanding are based on traditional continuum models. This workshop focuses first on the phase diagrams and phase transitions of materials known to be composed of molecular networks. These phase properties characteristically contain remarkable features, such as intermediate phases that lead to reversibility windows in glass transitions as functions of composition. These features arise as a result of self-organization of the internal structures of the intermediate phases. In the protein case, this self-organization is the basis for protein folding. The second focus is on partly disordered electronic materials whose phase properties exhibit the same remarkable features. In fact, the phenomenon of High Temperature Superconductivity, discovered by Bednorz and Mueller in 1986, and now the subject of 75,000 research papers, also arises from such an intermediate phase. More recently discovered electronic phenomena, such as giant magnetoresistance, also are made possible only by the existence of such special phases. This book gives an overview of the methods and results obtained so far by studying the characteristics and properties of nanoscale self-organized networks. It demonstrates the universality of the network approach over a range of disciplines, from protein folding to the newest electronic materials.

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, materials science, and engineering, with length scales ranging from Angstroms up to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area of current interest and brings together leading experts to give an up-to-date discussion of their work and the work of others. Each article contains enough references that the interested reader can access the relevant literature. Thanks are given to the Center for Fundamental Materials Research at Michigan State University for supporting this series. M.F. Thorpe, Series Editor E-mail: [email protected] East Lansing, Michigan, November 200 I v PREFACE The study of the atomic structure of crystalline materials began at the beginning of the twentieth century with the discovery by Max von Laue and by W.H. and W.L. Bragg that crystals diffract x-rays. At that time, even the existence of atoms was controversial.

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, materials science and engineering, with length scales ranging from Angstroms up to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area of current interest and brings together leading experts to give an up-to-date discussion of their work and the work of others. Each article contains enough references that the interested reader can access the relevant literature. Thanks are given to the Center for Fundamental Materials Research at Michigan State University for supporting this series. M.F. Thorpe, Series Editor E-mail: thorpe @ pa.msu.edu East Lansing, Michigan PREFACE One of the most challenging problems in the study of structure is to characterize the atomic short-range order in materials. Long-range order can be determined with a high degree of accuracy by analyzing Bragg peak positions and intensities in data from single crystals or powders. However, information about short-range order is contained in the diffuse scattering intensity. This is difficult to analyze because it is low in absolute intensity (though the integrated intensity may be significant) and widely spread in reciprocal space."

Although rigidity has been studied since the time of Lagrange (1788) and Maxwell (1864), it is only in the last twenty-five years that it has begun to find applications in the basic sciences. The modern era starts with Laman (1970), who made the subject rigorous in two dimensions, followed by the development of computer algorithms that can test over a million sites in seconds and find the rigid regions, and the associated pivots, leading to many applications. This workshop was organized to bring together leading researchers studying the underlying theory, and to explore the various areas of science where applications of these ideas are being implemented.

The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials, with particular emphasis on electronic properties and device applications. In order to limit the material to a manageable amount, the meeting was concerned almost exclusively with semiconducting materials. This volume should be regarded as a follow-on to the NATO ASI held in Sozopol, Bulgaria in 1996 and published as "Amorphous Insulators and Semiconductors" edited by M.F. Thorpe and M.1. Mitkova (Kluwer Academic Publishers, NATO ASI series, 3 High Technology - Vol. 23). The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas, and the lectures and seminars that were given are presented in this volume. During the first week of the meeting, an emphasis was placed on introductory lectures while the second week focused more on research seminars. There were two very good poster sessions that generated a lot of discussion, but these are not reproduced in this volume as the editors wanted to have only larger contributions to make the proceedings more coherent.

The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials. In order to limit the material to a manageable amount, the meeting was concerned exclusively with insulating and semiconducting materials. The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas and the lectures and seminars that were given are presented in this volume. During the first week of the meeting. an emphasis was placed on introductory lectures, mainly associated with questions relating to the glass-formation and the structure of glasses. The second week focused more on research seminars. Each day of the meeting. about four posters were presented during the coffee breaks, and these formed an important focus for discussions. The posters are not reproduced in this volume as the editors wanted to have only larger contributions to make this volume more coherent. This volume is organized into four sections, starting with general considerations of the glass forming ability and techniques for the preparation of different kinds of glasses.

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, and engineering, with length scales ranging from Angstromsup to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area ofcurrent interest and brings together leading experts to give an up-to-date discussion of their work and the work ofothers. Each article contains enough references that the interested reader can accesstherelevant literature. Thanks aregiven to the Center forFundamental Materials Research atMichigan State University forsupportingthis series. M.F. Thorpe, Series Editor E-mail: [email protected] EastLansing, Michigan, September, 1995 PREFACE This book records selected papers given at an interdisciplinary Symposium on Access in Nanoporous Materials held in Lansing, Michigan, on June 7-9, 1995. Broad interest in the synthesis of ordered materials with pore sizes in the 1.0-10 nm range was clearly manifested in the 64 invited and contributed papers presented by workers in the formal fields of chemistry, physics, and engineering. The intent of the symposium was to bring together a small number ofleading researchers within complementary disciplines to share in the diversity of approaches to nanoporous materials synthesis and characterization."

Advances in nanoscale science show that the properties of many materials are dominated by internal structures. In molecular cases, such as window glass and proteins, these internal structures obviously have a network character. However, in many partly disordered electronic materials, almost all attempts at understanding are based on traditional continuum models. This workshop focuses first on the phase diagrams and phase transitions of materials known to be composed of molecular networks. These phase properties characteristically contain remarkable features, such as intermediate phases that lead to reversibility windows in glass transitions as functions of composition. These features arise as a result of self-organization of the internal structures of the intermediate phases. In the protein case, this self-organization is the basis for protein folding. The second focus is on partly disordered electronic materials whose phase properties exhibit the same remarkable features. In fact, the phenomenon of High Temperature Superconductivity, discovered by Bednorz and Mueller in 1986, and now the subject of 75,000 research papers, also arises from such an intermediate phase. More recently discovered electronic phenomena, such as giant magnetoresistance, also are made possible only by the existence of such special phases. This book gives an overview of the methods and results obtained so far by studying the characteristics and properties of nanoscale self-organized networks. It demonstrates the universality of the network approach over a range of disciplines, from protein folding to the newest electronic materials.

Although rigidity has been studied since the time of Lagrange (1788) and Maxwell (1864), it is only in the last twenty-five years that it has begun to find applications in the basic sciences. The modern era starts with Laman (1970), who made the subject rigorous in two dimensions, followed by the development of computer algorithms that can test over a million sites in seconds and find the rigid regions, and the associated pivots, leading to many applications. This workshop was organized to bring together leading researchers studying the underlying theory, and to explore the various areas of science where applications of these ideas are being implemented.

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, materials science, and engineering, with length scales ranging from Angstroms up to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area of current interest and brings together leading experts to give an up-to-date discussion of their work and the work of others. Each article contains enough references that the interested reader can access the relevant literature. Thanks are given to the Center for Fundamental Materials Research at Michigan State University for supporting this series. M.F. Thorpe, Series Editor E-mail: [email protected] East Lansing, Michigan, November 200 I v PREFACE The study of the atomic structure of crystalline materials began at the beginning of the twentieth century with the discovery by Max von Laue and by W.H. and W.L. Bragg that crystals diffract x-rays. At that time, even the existence of atoms was controversial.

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, materials science and engineering, with length scales ranging from Angstroms up to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area of current interest and brings together leading experts to give an up-to-date discussion of their work and the work of others. Each article contains enough references that the interested reader can access the relevant literature. Thanks are given to the Center for Fundamental Materials Research at Michigan State University for supporting this series. M.F. Thorpe, Series Editor E-mail: thorpe @ pa.msu.edu East Lansing, Michigan PREFACE One of the most challenging problems in the study of structure is to characterize the atomic short-range order in materials. Long-range order can be determined with a high degree of accuracy by analyzing Bragg peak positions and intensities in data from single crystals or powders. However, information about short-range order is contained in the diffuse scattering intensity. This is difficult to analyze because it is low in absolute intensity (though the integrated intensity may be significant) and widely spread in reciprocal space."

The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials. In order to limit the material to a manageable amount, the meeting was concerned exclusively with insulating and semiconducting materials. The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas and the lectures and seminars that were given are presented in this volume. During the first week of the meeting. an emphasis was placed on introductory lectures, mainly associated with questions relating to the glass-formation and the structure of glasses. The second week focused more on research seminars. Each day of the meeting. about four posters were presented during the coffee breaks, and these formed an important focus for discussions. The posters are not reproduced in this volume as the editors wanted to have only larger contributions to make this volume more coherent. This volume is organized into four sections, starting with general considerations of the glass forming ability and techniques for the preparation of different kinds of glasses.

The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials, with particular emphasis on electronic properties and device applications. In order to limit the material to a manageable amount, the meeting was concerned almost exclusively with semiconducting materials. This volume should be regarded as a follow-on to the NATO ASI held in Sozopol, Bulgaria in 1996 and published as "Amorphous Insulators and Semiconductors" edited by M.F. Thorpe and M.1. Mitkova (Kluwer Academic Publishers, NATO ASI series, 3 High Technology - Vol. 23). The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas, and the lectures and seminars that were given are presented in this volume. During the first week of the meeting, an emphasis was placed on introductory lectures while the second week focused more on research seminars. There were two very good poster sessions that generated a lot of discussion, but these are not reproduced in this volume as the editors wanted to have only larger contributions to make the proceedings more coherent.

The papers in this volume are from the workshop on Protein Flexibility and Folding held in Traverse City, Michigan from August 13 - 17, 2000. The purpose of the workshop was to bring together diverse people interested in protein folding and flexibility from theoretical, computational and experimental perspectives and to encourage discussion on new approaches and challenges in the field. The workshop was held in the Park Plaza Hotel with 43 participants, including 24 invited speakers. The small size of the group made for easy exchanges, and many of the presentations by the invited speakers appear in this volume. There was also a very lively poster session.
The three-day workshop was organized so that the first day covered Flexibility and Dynamics, the second day Folding and Unfolding, and the third day Evolution and Design. This area of science is particularly appealing as it spans a range of questions from very fundamental - as to how proteins fold in such short times with such reliability - to applications such as the role of flexibility in screening for new ligands to a protein. Protein flexibility and folding have attracted the attention of scientists from many disciplines, ranging from mathematics to molecular biology. The scientists at the workshop represented the breadth of challenges in theory and applications that keep this field so fascinating and dynamic.
The present volume is organized along these same lines.