Download or read book Angular Momentum Wave Functions Constructed by Projection Operators Technical Note written by and published by . This book was released on 1958 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The conventional method of constructing wave functions of pure angular momentum for a composite system is based on the idea of coupling the angular momenta of the constituents. Instead of this synthetic method, an analytical approach is here introduced. It is pointed out that an arbitrary trial wave function for the total system in a unique way must be resolvable into orthogonal components of pure angular momentum associated with different quantum numbers. A particular component can be selected by means of certain 'projection operators', which annihilate all components except the one desired. Such a projection operator is simply a product of commuting factors, each one of which annihilates a specific eigenfunction to the angular momentum under consideration. Physically this idea is of importance, since one can now start out from a rough model wave function based essentially on qualitative arguments, for instance of the independent-particle type, and then obtain a mathematically and physically much better trial function by selecting the particular component of the original function which has the correct symmetry type desired. The projection operators are studied in some detail both as products and in expanded form. The case of degenerate subspaces of the same angular momentum quantum numbers is discussed, and the problem of constructing an orthogonal subset of functions is solved by a simple elimination procedure; the connection with the conventional seniority idea is briefly discussed.
Download or read book NASA Technical Note written by and published by . This book was released on 1970 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Angular Momentum Wave Functions Contructed by Projection Operators written by Per-Olov Löwdin and published by . This book was released on 1958 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel Electronic Structure Theory General Innovations and Strongly Correlated Systems written by and published by Academic Press. This book was released on 2018-01-03 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel Electronic Structure Theory: General Innovations and Strongly Correlated Systems, Volume 76, the latest release in the Advances in Quantum Chemistry series presents work and reviews of current work in quantum chemistry (molecules), but also includes scattering from atoms and solid state work of interest in physics. Topics covered in this release include the Present Status of Selected Configuration Interaction with Truncation Energy Error, Recent Developments in Asymptotic Expansions from Numerical Analysis and Approximation Theory, The kinetic energy Pauli enhancement factor and its role in determining the shell structure of atoms and molecules, Numerical Hartree-Fock and Many-Body Calculations for Diatomic Molecules, and more. - Provides reports on current work in molecular and atomic quantum mechanics - Contains work reported by many of the best scientists in the field - Presents the latest release in the Advances in Quantum Chemistry series
Download or read book Long range Atomic Interaction Potentials for Nitrogen written by Willard E. Meador and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computer Simulation of Liquids written by Michael P. Allen and published by Oxford University Press. This book was released on 2017-08-15 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a practical guide to molecular dynamics and Monte Carlo simulation techniques used in the modelling of simple and complex liquids. Computer simulation is an essential tool in studying the chemistry and physics of condensed matter, complementing and reinforcing both experiment and theory. Simulations provide detailed information about structure and dynamics, essential to understand the many fluid systems that play a key role in our daily lives: polymers, gels, colloidal suspensions, liquid crystals, biological membranes, and glasses. The second edition of this pioneering book aims to explain how simulation programs work, how to use them, and how to interpret the results, with examples of the latest research in this rapidly evolving field. Accompanying programs in Fortran and Python provide practical, hands-on, illustrations of the ideas in the text.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1975 with total page 1010 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AFOSR written by United States. Air Force. Office of Scientific Research and published by . This book was released on 1968 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Methods for Electron Molecule Collisions written by Franco A. Gianturco and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The collision of electrons with molecules and molecular ions is a fundamental pro cess in atomic and molecular physics and in chemistry. At high incident electron en ergies, electron-molecule collisions are used to deduce molecular geometries, oscillator strengths for optically allowed transitions, and in the case of electron-impact ionization, to probe the momentum distribution of the molecule itself. When the incident electron energy is comparable to or below those of the molecular valence electrons, the physics involved is particularly rich. Correlation and exchange effects necessary to describe such collision processes bear a close resemblance to similar efft:cts in the theory of electronic structure in molecules. Compound state formations, in the form of resonances and vir tual states, manifest themselves in experimental observables which provide details of the electron-molecule interactions. Ro-vibrational excitations by low-energy electron collisions exemplify energy transfer between the electronic and nuclear motion. The role of nonadiabatic interaction is raised here. When the final vibrational state is in the continuum, molecular dissociation occurs. Dissociative recombination and dissociative attachment are examples of such fragmentation processes. In addition to its fundamental nature, the study of electron-molecule collisions is also motivated by its relation to other fields of study and by its technological appli cations. The study of planetary atmospheres and the interstellar medium necessarily involve collision processes of electrons with molecules and molecular ions.
Download or read book Diatomic Interaction Potential Theory written by Jerry Goodisman and published by Elsevier. This book was released on 2012-12-02 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diatomic Interaction Potential Theory, Volume 1: Fundamentals deals with the theoretical approaches to calculations for diatomic systems in their ground states. More specifically, this book considers the problem of calculating the wave function and energy for the lowest state of a system of N electrons moving in the field of two fixed point charges (the nuclei of a diatomic system) separated by a distance R. Comprised of three chapters, this volume opens with an introduction to the nature of an interatomic interaction potential or potential energy curve. The separation of nuclear from electronic motions is considered, along with the methods used to measure potential energy curves. The next chapter presents a qualitative discussion of potential energy curves, with emphasis on the effects to be expected when two atomic systems are allowed to interact at large separation. The final chapter looks at the main approaches to schemes of calculation: variation theory, perturbation theory, the virial and Hellmann-Feynman theorems, local energy principles, and quantum statistical theories. This monograph will be a useful resource for students and teachers of physical chemistry.
Download or read book Selected Topics in Molecular Physics written by Enrico Clementi and published by . This book was released on 1972 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Autoionization written by Aaron Temkin and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: About five years ago, Professor P. G. Burke asked me to edit a sequel to an earlier book-Autoionization: Theoretical, Astrophysical, and Laboratory Experimental Aspects, edited by A. Temkin, Mono Book Corp. , Baltimore, 1966. Because so much time had gone by and so much work had been done, the prospect of updating the 1966 volume seemed out of the question. In 1965 the phenomenon of autoionization, although long known, was just starting to emerge from a comparatively intuitive stage of understanding. Three major developments characterized that development: In solar (astro-)physics, Alan Burgess (1960) had provided the resolution of the discrepancy of the temperature of the solar corona as observed versus that deduced from ionization balance calculations, by including the process of dielectronic recombination in the calculation; Madden and Codling (1963) had just performed their classic experiment revealing spectroscopically sharp lines in the midst of the photoionization continuum of the noble gases; and Feshbach (1962) had developed a theory with the explicit introduction of projection operators, which for the first time put the calculation of auto ionization states on a firm theoretical footing. There were important additional contributions made at that time as well; nevertheless, without going into further detail, we were able to include in our 1966 volume, in spite of its modest size, a not too incomplete survey of the important developments at that time. To do the equivalent now would be virtually impossible.
Download or read book Atomic Structure written by Winfred Oliver Milligan and published by . This book was released on 1959 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure of Medium Mass Nuclei written by V K B Kota and published by CRC Press. This book was released on 2016-12-12 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Medium heavy nuclei with mass number A=60-90 exhibit a variety of complex collective properties, provide a laboratory for double beta decay studies, and are a region of all heavy N=Z nuclei. This book discusses these three aspects of nuclear structure using Deformed Shell Model and the Spin-Isospin Invariant Interacting Boson Model naturally generated by fermionic SO(8) symmetry. Using these two models, the book describes properties of medium heavy nuclei with mass number A=60-90. It provides a good reference for future nuclear structure experiments using radioactive ion beam (RIB) facilities. Various results obtained by the authors and other research groups are also explained in this book.
Download or read book Proceedings of the Robert A Welch Foundation Conferences on Chemical Research written by and published by . This book was released on 1959 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coherent States written by John R. Klauder and published by World Scientific. This book was released on 1985 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a review on coherent states and some of their applications. The usefulness of the concept of coherent states is illustrated by considering specific examples from the fields of physics and mathematical physics. Particular emphasis is given to a general historical introduction, general continuous representations, generalized coherent states, classical and quantum correspondence, path integrals and canonical formalism. Applications are considered in quantum mechanics, optics, quantum chemistry, atomic physics, statistical physics, nuclear physics, particle physics and cosmology. A selection of original papers is reprinted.
