Download or read book Structure and Screening in Molecular and Metallic Hydrogen at High Pressure written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-14 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variational wavefunction is used to express the (spin restricted) Hartree-Fock energy as reciprocal lattice sums for static lattice FCC monatomic hydrogen and diatomic Pa3 molecular hydrogen. In the monatomic phase the hydrogenic orbital range closely parallels the inverse Thomas-Fermi wavevector; the corresponding energy E has a minimum of -0.929 Ryd/electron at r sub s = 1.67. For the diatomic phase E(r sub s) is similar, but the constituent energies, screening, and bond length reflect a qualitative change in the nature of the solid at r sub s = 2.8. This change is interpreted in terms of a transition from protons as structural units (at high density) to weakly interacting models (at low density). Insensitivity of the total energy to a rapid fall in the bond length suggests association with the rotational transition where the rapid molecular orientations characteristic of high pressures disappear and the molecules rotate freely at low pressure. Wood, D. M. and Ashcroft, N. W. Unspecified Center NASA-CR-164467, MSC-4460 NSG-7487...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular and Metallic Hydrogen written by Marvin Ross and published by . This book was released on 1977 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a comprehensive review and analysis of the published data on metallic hydrogen and a summary of the properties of molecular hydrogen that are required to determine the molecular-to-metallic hydrogen transition pressure. The best available effective interaction potential is utilized in calculating the equation of state for solid molecular hydrogen. The equation of state of metallic hydrogen is determined by four different methods and the possible range of molecular-to-metallic hydrogen is largely responsible for the wide discrepancy in calculations of the transition pressure. Metastability of metallic hydrogen is discussed and the experimental high- pressure research pertinent to the determination of molecular-to-metallic hydrogen transition pressure is reviewed.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1985 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Attempt to Metallize Hydrogen at Very High Pressures written by and published by . This book was released on 1992 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic hydrogen is potential candidate as a high energy density material. The possibility of metallizing hydrogen by submitting it to very high pressures has been experimentally investigated. Great advances have been made in this study. Pressures as high as 2.3 megabar on hydrogen have been obtained in diamond anvil cells (DACs). Several new phase transitions have been observed in the megabar pressure region. One of these, called the hydrogen-A (H-A) phase is believed to be the metallic molecular phase of hydrogen. However, current limitations on the optical techniques available to diamond anvil cell research have prevented direct determination of the conductive state and techniques for the direct measurement of the dc electrical conductivity are still under development. Band structure calculations have shown that metallization may be profoundly affected by molecular orientational order. Other observed phase transitions are believed to be associated with orientational order and fundamental changes in the molecular symmetry at high densities. A pulsed NMR system for studying very small samples of hydrogen has been constructed and will be useful in analyzing the nature of high density hydrogen. Metallic hydrogen, high pressure.
Download or read book Hydrogen in Metals Application oriented properties written by G. Alefeld and published by . This book was released on 1978 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Metal Hydrogen System written by Yuh Fukai and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: I think it is expedient here to clearly specify the readership for whom this book is intended. Some readers might infer from the title that this is a data book convenient for occasional reference purposes. Most of the data on the bulk properties and a comprehensive list of publications are indeed compiled here, will be found useful as they are. The primary purpose of the book is, however, and rather to provide a coherent and consistent description of the basic bulk properties of the metal-hydrogen system, ranging from macroscopic properties such as solubilities and phase diagrams to microscopic properties such as atomistic states and diffusion. The emphasis has been placed on the physics of how these properties actually come about. This structure of the book is considered to be useful, and even necessary, not only for physicists but also for researchers interested in the materials-science aspects of the system. Who could have anticipated that the solubility of hydrogen in iron reaches a level as high as [H]/[Fe] ~ 1 under a hydrogen pressure of 10 GPa; who could have anticip ated that the diffusivity of hydrogen in metals increases at low temperatures; who could unravel the mechanism of "cold" fusion (if this indeed exists), without a basic understanding of the metal-hydrogen system? Obviously, these prob lems are not only of academic interest but also have profound technical implications.
Download or read book LBL Research Review written by and published by . This book was released on 1980 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intrinsic Structures and Properties of Energetic Materials written by Chaoyang Zhang and published by Springer Nature. This book was released on 2023-06-30 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the intrinsic structures of all kinds of energetic compounds and some structure–property relationships therein. Energetic materials are a class of energy materials that can transiently release a large amount of gases and heat by self-redox after stimulated and usually refer to explosives, propellants and pyrotechnics. Nowadays, in combination with various theories and simulation-aided material design technologies, many new kinds of energetic materials like energetic extended solids, energetic ionic salts, energetic metal organic frames, energetic co-crystals and energetic perovskites have been created, in addition to traditional energetic molecular crystals. It is somewhat dazzling, and an issue of how we can understand these new types of energetic materials is raised. In the past about 20 years, we were immersed in the computational energetic materials. By means of defining a concept of intrinsic structures of energetic materials, which refers to the crystal packing structure of energetic materials, as well as molecule for molecular solid specially, the microscopic structures have been mostly clarified, and related with many macroscopic properties and performances, with molecular simulations. This book presents our understanding about it. Thereby, a simply and new way to readily understand energetic materials is expected to be paved, based on this book. It contains energetic molecular crystals, energetic ionic crystals, energetic atomic crystals, energetic metallic crystals and energetic mixed-type crystals and the substructures closest to crystal packing. Meanwhile, the common intermolecular interactions in energetic crystals will be introduced. In addition, theoretical and simulation methods for treating the intrinsic structures will be briefed, as they are the main tools to reveal the molecules and crystals. Besides, the polymorphism as a level of intrinsic structures will be briefly discussed. In the final of this book, we introduce the crystal engineering of energetic materials. This book features the first proposal of intrinsic structure and crystal engineering of energetic materials and the understanding of the properties and performances of energetic materials by maintaining a concept that structure determines property. It helps to promote the rationality in creating new energetic materials, rather than increase experience.
Download or read book Introduction to Structural Chemistry written by Stepan S. Batsanov and published by Springer Science & Business Media. This book was released on 2012-11-29 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concise description of models and quantitative parameters in structural chemistry and their interrelations, with 280 tables and >3000 references giving the most up-to-date experimental data on energy characteristics of atoms, molecules and crystals (ionisation potentials, electron affinities, bond energies, heats of phase transitions, band and lattice energies), optical properties (refractive index, polarisability), spectroscopic characteristics and geometrical parameters (bond distances and angles, coordination numbers) of substances in gaseous, liquid and solid states, in glasses and melts, for various thermodynamic conditions. Systems of metallic, covalent, ionic and van der Waals radii, effective atomic charges and other empirical and semi-empirical models are critically revised. Special attention is given to new and growing areas: structural studies of solids under high pressures and van der Waals molecules in gases. The book is addressed to researchers, academics, postgraduates and advanced-course students in crystallography, materials science, physical chemistry of solids.
Download or read book Energy and Water Development Appropriations for 2018 written by United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water Development and published by . This book was released on 2017 with total page 1360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindeks written by and published by . This book was released on 1987 with total page 1414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Physics vol 3 2011 written by Dmitri Rabounski and published by Infinite Study. This book was released on with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Journal on Advanced Studies in Theoretical and Experimental Physics, including Related Themes from Mathematics
Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1832 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Pressure and Low Temperature Physics written by J.A. Woollam and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: High pressure science is a rapidly growing diverse fi. e1d. The high pressure technique has become a powerful tool for both the study and preparation of materials. In spi. te of the many high pressure conferences held in recent years, I felt that there was a need for scientists within a well-defined area (not bound merely by the common experimental technique) to meet in an atmosphere conducive to frank exchange and close interaction. In this spirit, the Cleveland State University hosted such a conference from July 20 to 22, 1977, in which the physics of solids under high pressures and at low tempera tures was specifically examined. Both the original and review papers presented at the conference and the candid discussions following their presentations appear in this volume. They clearly cover a rather complete spectrum of current research in the physics of solids at high pressures and low temperatures. I wish to thank the National Aeronautics and Space Administra tion, the Office of Naval Research and the National Science Founda tion for their financial support of the conference. In addition, I wish especially to thank Steinar Huang for his unceasing assistance in arranging this conference. I also wish to thank him and Francis Stephenson for their assistance in preparing this book. C. W. Chu, Chairman, International Conference on High Pressure and Low Temperature Physics v Contents HYDROGEN AND METAL-HYDRIDES (Chairman: I. Spain) PROSPECTS FOR METALLIC HYDROGEN 1 A. L.
Download or read book High Pressure Phenomena written by M. Bernasconi and published by IOS Press. This book was released on 2002 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reports on the Enrico Fermi School, the first one dedicated to advanced organic materials. The main research results and open problems in science and technology of organic nanostructures have been discussed here - in particular, growth techniques, electronic and optical properties and device applications. The necessary background material has been covered and interdisciplinary aspects have been emphasized with the aim of a unified approach to the basic physical phenomena bridging the gap between standard graduate courses and the state of the art in the field.
Download or read book Vision 21 Space Travel for the Next Millennium written by and published by . This book was released on 1991 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
