This book has its or1g1n in a NATO Summer School organized from June 25 to July 7 1979, in Menton, France. The purpose of this School was a comparative study of the various aspects of vibra tional spectroscopy in molecular liquids and solids. This field has been rapidly expanding in the last decade; unfortunately, its development took place independently for liquids and for solids. In these circumstances, the comparison of the basic concepts and techniques used in these two branches of physics appeared as a necessity. The lectures given at the Menton Advanced Study Institute, as well as the exceptionally fruitful and lively discussions which followed them confirmed this point of view. The need of putting together these lectures, in the form of a monograph, clearly appeared during the ASI and the lecturers accepted to write down the material they presented at the Institute, improved thanks to the remarks of the participants. It is the result of this collective work which appears in the familiar Plenum Series.

This book has its or1g1n in a NATO Summer School organized from June 25 to July 7 1979, in Menton, France. The purpose of this School was a comparative study of the various aspects of vibra tional spectroscopy in molecular liquids and solids. This field has been rapidly expanding in the last decade; unfortunately, its development took place independently for liquids and for solids. In these circumstances, the comparison of the basic concepts and techniques used in these two branches of physics appeared as a necessity. The lectures given at the Menton Advanced Study Institute, as well as the exceptionally fruitful and lively discussions which followed them confirmed this point of view. The need of putting together these lectures, in the form of a monograph, clearly appeared during the ASI and the lecturers accepted to write down the material they presented at the Institute, improved thanks to the remarks of the participants. It is the result of this collective work which appears in the familiar Plenum Series.

This ASI was planned to make a major contribution to the teaching of the principles and methods used in liquid phase ~esearch and to encourage the setting up of collaborative projects, as advocated by the European Molecular Liquids Group (secretary: Dr J. Yarwood, University of Durham, U. K. ). During the past five years considerable progress has been made in studying molecular liquids. The undoubted advantages of international collaboration led to the formation of the European Molecular Liquids Group (EMLG) in July 1981. The activities of the EMLG were widely disseminated in a special session of the European Congress on Molecular Spectroscopy (EUCMOS) held in September 1981 (for details, see J. Mol. Structure, 80 (1982) 375 - 421). Following the success of this meeting, it was thought that the aims and objectives of the E~G would be best served by the organisation of a broader-based gathering designed to attract those interested in the study of the structure, dynamics and interactions in the liquid state. Thanks to the generous support by the Scientific Affairs Division of NATO, it was possible to hold a NATO ASI on Molecular Liquids at the Italian Centre of Stanford University, Florence, Italy during June-July 1983. This book is based on the lectures presented at that meeting. The contents of this volume cover the three broad areas of current liquid phase research: (a) Analytical theory.

In its combination of an advanced teaching standpoint with an emphasis on new perspectives and recent advances in the study of liquids formed by simple molecules, Molecular Liquids: New Perspectives in Physics and Chemistry provides a clear, understandable guide through the complexities of the subject. A wide range of topics is covered in the areas of intermolecular forces, statistical mechanics, the microscopic dynamics of simple liquids, thermodynamics of solutions, nonequilibrium molecular dynamics, molecular models for transport and relaxation in fluids, liquid simulations, statistical band shape theories, conformational studies, fast-exchange dynamics, and hydrogen bonding. The experimental techniques covered include: neutron scattering, X-ray diffraction, IR, Raman, NMR, quasielastic neutron scattering, and high-precision, time-resolved coherent Raman spectroscopy.

Proceedings of the NATO Advanced Study Institute, Luso, Portugal, September 22-October 3, 1991

A description of procedures for probing bond activation, H-bonded systems, molecular dynamical mechanisms, vibrational dephasing, simple liquids, and proteins and energy flow effects using ultrafast vibrational spectroscopy experiments. It discusses experimental and theoretical methods of ultrafast infrared and Raman measurements.

Inelastic neutron scattering (INS) is a spectroscopic technique in which neutrons are used to probe the dynamics of atoms and molecules in solids and liquids. This book is the first, since the late 1960s, to cover the principles and applications of INS as a vibrational-spectroscopic technique. It provides a hands-on account of the use of INS, concentrating on how neutron vibrational spectroscopy can be employed to obtain chemical information on a range of materials that are of interest to chemists, biologists, materials scientists, surface scientists and catalyst researchers. This is an accessible and comprehensive single-volume primary text and reference source.

This book is concerned with recent experimental and theoretical work dealing with phenomena created by the transient dipoles and polarizabilities produced by intermolecular interactions. The for mer produce absorption from the microwave to the optical regions of the spectrum and the latter produce Rayleigh and Raman scattering; such absorption and scattering would be absent without collisions. Static properties, such as dielectric constant, refractive index, and Kerr effect, also exhibit the effects of induced dipoles and polarizabilities. The first observation of an infrared absorption spectrum pro duced by the collisions of molecules which ordinarily do not have an allowed dipole transition was reported in 1949 (Crawford, Welsh, and Locke). The first observation of depolarized Rayleigh spectra due to collisions in atomic gases appeared in 1968 (McTague and Birnbaum). However, it was not until 1977 that the first conference dealing with collision-induced phenomena was organized by J. D. Poll at the University of Guelph. This conference was mainly concerned with studies of collision-induced absorption in gases. Light scat tering received more attention at the second meeting of the colli sion-induced community in 1978, at the E. Fermi Summer School on "Intermolecular Spectroscopy and Dynamical Properties of Dense Sys tems," organized by J. Van Kranendonk. However, the emphasis was still on collision-induced absorption in compressed gases, although some work on liquids, solid H , and related subjects such as ro 2 tational relaxation was included. The third induced phenomena con ference, organized by F.

With the development of lasers that can generate light 11 14 pulses ranging from 10- - 10- sec duration, and capable of 13 peak powers in excess of 10 watts scientists have been able to investigate the interactions of light with matter in a time and power domain not previously possible. These ultrashort laser pulses provide a powerful tool for the study of chemical phenomena at the most fundamental level. Many of the elementary processes of importance in chemistry including energy dissipa tion, molecular motions, structural and chemical changes occur on a very short time scale and thus require special approaches. Th~ use of ultrashort laser pulses to perturb and to probe systems of interest affords a direct approach to the time reso lution of very rapid chemical phenomena. It was recognition of the impact of these relatively new approaches to chemical phenomena that motivated NATO to sponsor a meeting on the applications of picosecond spectroscopy in chemistry. The primary aim of the NATO workshop was to gain some perspective on the status of the field in terms of present research activities, technological developments and if possible the difficult task of sensing future directions. The way we decided to approach these issues was to gather together the main contributors to the field, fortunately many of whom were able to attend, to present their work and to participate in what turned out to be lively discussions of the field.