Lattice defects of organic molecular crystals affect their optical or electrical properties by changing the local energy structure. Lattice defects also playa very important role in the chemical and physical properties, for example, as an active site of a catalyst or an initiating point of a solid state reaction. However, very little has been reported on the defect structure of real organic crystals. In the past ten years it became clear that the origin and the structure of the defects depend on the geometrical and chemical nature of the building units of the crystal, the molecules. Molecular size, form and anisotropy, charge distribution, etc. cause the characteristic structure of the defect. Accordingly, a defect structure found in one compound may not be found in others. The defect structure of an organic crystal cannot be defined solely by the displacement of the molecular center from the normal lattice site. A rotational displacement of a molecule is frequently accompanied by a parallel shift of the molecular center. In addition to the usual geometrical crystallographic defects, chemical defects are important too which originate, for example, from differences in the substitution sites of molecules carrying side groups. In order to reveal such defect structures, direct imaging of molecules by high resolution electron microscopy is the only direct method.

Calorimetry, as a technique for thermal analysis, has a wide range of applications which are not only limited to studying the thermal characterisation (e.g. melting temperature, denaturation temperature and enthalpy change) of small and large drug molecules, but are also extended to characterisation of fuel, metals and oils. Differential Scanning Calorimetry is used to study the thermal behaviours of drug molecules and excipients by measuring the differential heat flow needed to maintain the temperature difference between the sample and reference cells equal to zero upon heating at a controlled programmed rate. Microcalorimetry is used to study the thermal transition and folding of biological macromolecules in dilute solutions. Microcalorimetry is applied in formulation and stabilisation of therapeutic proteins. This book presents research from all over the world on the applications of calorimetry on both solid and liquid states of materials.

This book summarizes and records the recent notable advances in diverse topics in organic crystal chemistry, which has made substantial progress along with the rapid development of a variety of analysis and measurement techniques for solid organic materials. This review book is one of the volumes that are published periodically on this theme. The previous volume, published in 2015, systematically summarized the remarkable progress in assorted topics of organic crystal chemistry using organic solids and organic–inorganic hybrid materials during the previous 5 years, and it has been widely read. The present volume also shows the progress of organic solid chemistry in the last 5 years, with contributions mainly by invited members of the Division of Organic Crystal Chemistry of the Chemical Society of Japan (CSJ), together with prominent invited authors from countries other than Japan.

Nonlinear Optical Properties of Organic Molecules and Crystals, Volume 1 discusses the nonlinear optical effects in organic molecules and crystals, providing a classical distinction between quadratic and cubic processes. This book begins with a general overview of the basic properties of organic matter, followed by a review on the benefits derived from quantum-chemistry-based models and growth and characterization of high quality, bulk organic crystals and waveguided structures. A case study focusing on a specific material, namely urea, which exemplifies a situation in which transparency in the UV region has been purposely traded for nonlinear efficiency is also deliberated. This text concludes with a description of a type of trade-off between the unpredictable orientation of molecules in crystalline media, polarity of liquid-crystalline structures, and dominant electronic contribution to the electro-optic effect. This publication is beneficial to solid-state physicists and chemists concerned with nonlinear optical properties of organic molecules and crystals.

: This book is based on research conducted on the growth and characterization of nonlinear optical crystals. Due to the significance of crystals in contemporary technology, crystal growth has been the focus of extensive research in both solid-state physics and materials science. This book serves as an introduction to the growth phenomena, specifics of growth processes, nonlinear optical phenomena, and characterization methods that are being used for the analysis. The book is divided into three chapters: The first chapter focuses on the experimental techniques of crystal growth. It outlines the several ways that crystals grow based on the phases they go through, such as solid-solid phase transition, liquid-solid phase transformation, and vapour-solid phase transformation. The optimization methods for growing high-quality single crystals are thoroughly presented. The benefits and drawbacks of methods of growth are reviewed. The second chapter explains the theory of nonlinear optical phenomena. The selection criteria for nonlinear optical materials are reviewed. The history of nonlinear optics and the various types of nonlinear optical materials are discussed. The role of amino acids in the formation of nonlinear optical crystals is well explained. The third chapter discusses characterization procedures that are essential in determining the quality of crystals. The several characterization mechanisms including the molecular structure, chemical composition, surface morphology, optical properties, dielectric properties, mechanical behavior, and thermal properties necessary for crystal analysis are described. We hope that this book will be valuable to researchers and students.