This is the first edited volume that features two important frameworks, Hückel and quantum chemical topological analyses. The contributors, which include an array of academics of international distinction, describe recent applications of such topological methods to various fields and topics that provide the reader with the current state-of-the-art and give a flavour of the wide range of their potentialities.

Quantum Crystallography is a novel scientific discipline combining quantum chemistry methods and crystal structure determination. The current book describes quantum-mechanical approaches to obtain crystallographic data of enhanced value and explains how they correlate with real diffraction and scattering experiments. In particular, the book covers DFT, Clinton equations, KEM and QTAIM methods and their applications in crystallographic studies.

Computational approaches offer researchers unique insights into the structure, characteristics, and properties of macromolecules. However, with applications across a broad range of areas, various methods have been developed for exploring macromolecules in in silico; therefore, it can be difficult for researchers to select the most appropriate method for their specific needs. Covering both biopolymers and synthetic polymers, In-Silico Approaches to Macromolecular Chemistry familiarizes readers with the theoretical tools and software appropriate for such studies. In addition to providing essential background knowledge on both computational tools and macromolecules, the book presents in-depth studies of in silico macromolecule chemistry, discusses and compares these with experimental studies, and highlights the future potential for such approaches. Written by specialists in their respective fields, this book helps students, researchers, and industry professionals gain a clear overview of the field, and furnishes them with the knowledge needed to understand and select the most appropriate tools for conducting and analyzing computational studies. - Highlights in silico studies of both bio and synthetic macromolecules in one book - Supports both learners and experts though a combination of detailed guidance and perspectives on the future potential for in silico approaches to macromolecules - Familiarizes readers with theoretical tools and software helping them select the best approach for their specific needs

Discover theoretical, methodological, and applied perspectives on electron density studies and density functional theory Electron density or the single particle density is a 3D function even for a many-electron system. Electron density contains all information regarding the ground state and also about some excited states of an atom or a molecule. All the properties can be written as functionals of electron density, and the energy attains its minimum value for the true density. It has been used as the basis for a quantum chemical computational method called Density Functional Theory, or DFT, which can be used to determine various properties of molecules. DFT brings out a drastic reduction in computational cost due to its reduced dimensionality. Thus, DFT is considered to be the workhorse for modern computational chemistry, physics as well as materials science. Electron Density: Concepts, Computation and DFT Applications offers an introduction to the foundations and applications of electron density studies and analysis. Beginning with an overview of major methodological and conceptual issues in electron density, it analyzes DFT and its major successful applications. The result is a state-of-the-art reference for a vital tool in a range of experimental sciences. Readers will also find: A balance of fundamentals and applications to facilitate use by both theoretical and computational scientists Detailed discussion of topics including the Levy-Perdew-Sahni equation, the Kohn Sham Inversion problem, and more Analysis of DFT applications including the determination of structural, magnetic, and electronic properties Electron Density: Concepts, Computation and DFT Applications is ideal for academic researchers in quantum, theoretical, and computational chemistry and physics.

DNA is the most important biomolecule ever discovered. Indeed, this molecule bears genetic information from one generation to another. In this regard, DNA bases have a key role in transferring genetic information and data safely. However, there are cellular, genetic, and environmental factors that may damage the different parts of DNA molecules. These damages may result in mutations and cell death. As such, several DNA repair mechanisms have evolved. Over three sections, this book examines many of these mechanisms.

Proceedings of the Seventh International Symposium on the Photochemistry and Photophysics of Coordination Compounds Elmau/FRG, March 29-April 2, 1987

The quantum phenomena of tunneling and interference show up not only in the microscopic world of atoms and molecules, but also in cold materials of the real world, such as metals and semiconductors. Though not fully macroscopic, such mesoscopic systems contain a huge number of particles, and the holistic nature of quantum mechanics becomes evident already in simple electronic measurements. The measured quantity fluctuates as a function of applied fields in an unpredictable, yet reproducible way. Despite this fingerprint character of fluctuations, their statistical properties are universal, i.e. they are the same for a large class of different mesoscopic systems, having only very few parameters in common. Localization of electrons is a dramatic effect of destructive interference. As a consequence a metal can become an insulator while reaching mesoscopic scales.Based on elementary quantum and statistical physics, this text introduces the theory of mesoscopic electron systems. It focuses on universal characteristics of fluctuations and on the localization mechanism. General concepts and methods are stressed, such as scaling laws for distribution functions. Tools from condensed matter theory are used flexibly. Involved technical details are skipped so as to present a broad overview of the field, including topics like quantum dots, the quantum Hall effect and a number of the most recent developments.

This new book brings together the latest information on intermolecular bonding within molecular crystals, providing a very useful introductory text for graduates.