Calculation of NMR and EPR Parameters


Book Description

This is the first book to present the necessary quantum chemical methods for both resonance types in one handy volume, emphasizing the crucial interrelation between NMR and EPR parameters from a computational and theoretical point of view. Here, readers are given a broad overview of all the pertinent topics, such as basic theory, methodic considerations, benchmark results and applications for both spectroscopy methods in such fields as biochemistry, bioinorganic chemistry as well as with different substance classes, including fullerenes, zeolites and transition metal compounds. The chapters have been written by leading experts in a given area, but with a wider audience in mind. The result is the standard reference on the topic, serving as a guide to the best computational methods for any given problem, and is thus an indispensable tool for scientists using quantum chemical calculations of NMR and EPR parameters. A must-have for all chemists, physicists, biologists and materials scientists who wish to augment their research by quantum chemical calculations of magnetic resonance data, but who are not necessarily specialists in these methods or their applications. Furthermore, specialists in one of the subdomains of this wide field will be grateful to find here an overview of what lies beyond their own area of focus.










High Resolution NMR Spectroscopy


Book Description

The theory and quantum-chemical calculations of the spectral parameters of nuclear magnetic resonance (NMR) are well established in the case of diamagnetic, closed-shell molecules. In contrast, NMR calculations of paramagnetic, open-shell molecules (pNMR) are scarce, limited by both assumptions within the underlying theoretical background as well as the availability of computational implementations. We discuss the systematic development of pNMR theory that recently culminated in a novel, general and systematic electronic structure approach for the shielding tensor and the associated chemical shift for paramagnetic, open-shell atoms, molecules, and nonmetallic solids. The approach has now been extended for the first time to a higher than doublet spin state as well as arbitrary spatial symmetry. The approach is formulated without reference to spin susceptibility, in contrast to the contemporary experimental procedure and approximate quantum-chemical treatment of axial zero-field splitting. As a result of the systematic procedure, all the temperature-dependent hyperfine shielding terms are generalized and, for example, the leading-order nonrelativistic dipolar term now provides an isotropic chemical shift contribution for species with triplet and higher spin multiplicity. Recent first-principles quantum-chemical calculations of pNMR chemical shifts are reviewed both using the novel theory as well as earlier approaches.




International Conference on Quantum Chemical Calculations of NMR and EPR Parameters Held in Castle Smolenice, Slovak Republic on September 14-18 1998


Book Description

This is the final proceedings for Quantum Chemical Calculations of NMR and EPR Parameters, 15 September 1998 - 19 September 1998. This is an interdisciplinary conference. Topics include issues and new methods in the theory and computational techniques involved in Nuclear Magnetic Resonance (NMR) and Electron Paramagnetic Resonance (EPR).







Calculation of Magnetic Properties of Paramagnetic Molecules


Book Description

While calculation of nuclear magnetic resonance (NMR) parameters and spectra areroutinely done for diamagnetic organic compounds, calculation of paramagnetic NMR(PNMR), in particular for compounds containing heavy elements, is at the forefront ofcomputational chemistry. Such calculations are often difficult, due to a variety of issues,including computational cost and extensive relativistic effects that require expensive cal-culations. This thesis outlines the use of DFT in the calculation of NMR and electronparamagnetic resonance (EPR) parameters of such compounds, including analysis of therole of relativistic effects and DFT delocalization error on selected heavy-metal complexes. Methods and code to generate PNMR shifts from calculated EPR data, and new analyticaltools, such as tools to analyze EPR parameters based on localized orbitals and currentdensity, are also discussed. An approach for analyzing spin and magnetization densitiesfrom multi-determinant wavefunction calculations is also outlined.




Principles and Applications of Density Functional Theory in Inorganic Chemistry I


Book Description

It is difficult to overestimate the impact that density functional theory has had on computational quantum chemistry over the last two decades. Indeed, this period has seen it grow from little more than a theoreticalcuriosity to become a central tool in the computational chemist s armoury. Arguably no area of ch- istry has benefited more from the meteoric rise in density functional theory than inorganic chemistry. the ability to obtainreliable results in feasible ti- scales on systems containing heavy elements such as the d and f transition - tals has led to an enormous growth in computational inorganic chemistry. The inorganic chemical literature reflects this growth; it is almost impossible to open a modern inorganic chemistry journal without finding several papers devoted exclusively or in part to density functional theory calculations. The real imp- tance of the rise in density functional theory in inorganic chemistry is undou- edly the much closer synergy between theory and experiment than was p- viously posible. In these volumes, world-leading researchers describe recent developments in the density functional theory and its applications in modern inorganic and b- inorganic chemistry. These articles address key issues key issues in both sol- state and molecular inorganic chemistry, such as spectroscopy, mechanisms, catalysis, bonding and magnetism. The articles in volume I are more focussed on advances in density functional methodogy, while those in Volume II deal more with applications, although this is by no means a rigid distinction.




Density Functional Calculations


Book Description

Density functional theory (DFT) ranks as the most widely used quantum mechanical method and plays an increasingly larger role in a number of disciplines such as chemistry, physics, material, biology, and pharmacy. DFT has long been used to complement experimental investigations, while now it is also regarded as an indispensable and powerful tool for researchers of different fields. This book is divided into five sections that include original chapters written by experts in their fields: "Method Development and Validation," "Spectra and Thermodynamics," "Catalysis and Mechanism," "Material and Molecular Design," and "Multidisciplinary Integration." I would like to express my sincere gratitude to all contributors and recommend this book to both beginners and experienced researchers.




Electronic Effects in Organic Chemistry


Book Description

The series Topics in Current Chemistry presents critical reviews of the present and future trends in modern chemical research. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field. Review articles for the individual volumes are invited by the volume editors. Readership: research chemists at universities or in industry, graduate students