A5082831450- Advanced Chemical Physics Studies
- X-ray Diffraction in Crystallography
- Quasicrystal Structures and Properties
- Research Data Management Practices
- Crystallization and Solubility Studies
- Scientific Computing and Data Management
- Surface and Thin Film Phenomena
- Graphene research and applications
- Semantic Web and Ontologies
- Data Quality and Management
- Semiconductor materials and devices
- Mineralogy and Gemology Studies
- Spectroscopy and Laser Applications
- Spectroscopy and Quantum Chemical Studies
- Boron and Carbon Nanomaterials Research
- Academic Publishing and Open Access
- Semiconductor materials and interfaces
- Theoretical and Computational Physics
- Physics of Superconductivity and Magnetism
- Advancements in Battery Materials
- Nonlinear Photonic Systems
- Graphite, nuclear technology, radiation studies
- Atmospheric and Environmental Gas Dynamics
- Diamond and Carbon-based Materials Research
- Material Dynamics and Properties
American Physical Society
2000-2018
University of Washington
1995-2000
Argonne National Laboratory
1993-1996
Seattle University
1995
Ricardo AEA (United Kingdom)
1994-1995
Indiana University Bloomington
1991-1992
Cornell University
1987-1990
Memorial University of Newfoundland
1984
By pseudopotential methods the electronic properties of quasicrystalline metal are examined from nearly-free-electron viewpoint. The procedure results in appearance band gaps associated with each quasicrystal reciprocal-lattice vector, and these lead to singularities both density states joint optical states. If observable by reflectivity, soft x-ray emission, or tunneling measurements, quantities will give information on several state.
Reproducibility and reusability of research results is an important concern in scientific communication science policy. A foundational element reproducibility the open persistently available presentation data. However, many common approaches for primary data publication use today do not achieve sufficient long-term robustness, openness, accessibility or uniformity. Nor they permit comprehensive exploitation by modern Web technologies. This has led to several authoritative studies...
In order to test the reliability of plane-wave and Gaussian-orbital based DFT methods for calculating reaction energies activation barriers, detailed calculations are performed several reactions involving gas phase silanes a simple model H2 desorption from Si(100)2×1 surface. This study is motivated in particular by apparent discrepancies between results cluster-model slab-model energy The obtained with different exchange-correlation functionals compared generally reliable QCISD(T) method...
Scanning tunneling microscopy measurements and first principles density functional theory calculations are used to study the rate of rotational transition Si ad-dimers on top surface dimer rows Si(100). The rotation relative population two stable orientations measured as a function applied electric field extract zero-field behavior. stability configurations is test accuracy various functionals for calculations.
We have studied diffusion of Ge into subsurface layers Si(100). Auger electron diffraction measurements show in the fourth layer after submonolayer growth at temperatures as low 500 degrees C. Density functional theory predictions equilibrium distributions are consistent with measurements. identify a surprisingly energy pathway resulting from interstitial formation third and layers. Doping significantly affects energy, suggesting that n-type doping may lead to sharper Si/Ge interfaces.
The binding energies and configurations for single Si adatoms on the Si(100) surface are investigated theoretically. Detailed comparisons between previously published new calculations using classical potentials, semiempirical formulations, density functional theory (DFT) made. DFT used both plane-wave-pseudopotential approach in a periodic slab geometry Gaussian-orbital based all-electron employing cluster geometries. In local-density approximation excellent agreement results was obtained....
The single-particle self-energy in a Landau quantized two-dimensional electron gas has been evaluated magnetic fields corresponding to arbitrarily large integer filling factors using the random-phase approximation. Quasiparticle energy separations have determined for levels near Fermi level and comparisons are made with values from recent activation measurements on integral quantum Hall plateaus. Conclusions drawn concerning field strengths required validity of commonly adopted strong-field...
We present theoretical results based on density functional theory and kinetic Monte Carlo simulations of silicon deposition address observations made in recently reported low temperature scanning tunneling microscopy studies. A mechanism is presented which explains dimer formation top the substrate's rows at 160 K up to room temperature, while between-row dimers longer strings adatoms (``diluted rows'') form higher temperature. crossover occurs around between two different mechanisms for...
ABSTRACT The Physical Review journals, particularly D (PRD) on particle and gravitational physics, have been near the centre of a revolution in electronic publishing caused by Los Alamos eprint archive, which began posting papers theoretical physics nearly eight years ago. This paper describes how PRD, responded thrived with this scientific communication, we expect things to continue develop future.
The nature of long-range many-body interactions in metallic fluids is examined with emphasis on their possible role the unique features these systems observed near liquid–vapor critical point. A reexamination recent theoretical results demonstrating existence van der Waals forces between ‘‘pseudoatoms’’ (ion cores and associated screening electrons) reveals a direct correspondence dispersion insulating systems. In limit high conduction electron number densities ρ, pseudoatoms have an...
We present a new interpretation of the Ewald technique that suggests simple rule to guide transformation any lattice sum into pair sums, one over original and other reciprocal lattice, both converging faster than power law in distance from origin. The sets conditions needed finding an approximation long-range part function being summed, it is Fourier transform this then appears reciprocal-lattice sum. Once such found, same can be used not only for sums Bravais lattices or with basis, but...
The tight-binding and local-density approximation (LDA) models of the electronic structure for ${\mathrm{C}}_{60}$ are applied to calculate transition strength four infrared-active vibrations. results correct order magntiude, but not accurate enough have predictive power. LDA give a much better description relative absolute strengths modes.
Inelastic-incoherent-neutron scattering can be a valuable nanostructural probe of ${\mathrm{H}}_{2}$-doped porous materials, provided the spectral peaks interpreted in terms crystal-field-split hydrogen-molecule energy levels, which represent signature local symmetry. Inelastic-neutron-scattering measurements as well extensive theoretical analyses have been performed on stage-2 Rb-intercalated graphite (Rb-GIC), with physisorbed ${\mathrm{H}}_{2}$, HD, and ${\mathrm{D}}_{2}$ [composition...
The Madelung constant associated with the electrostatic energy of perfect one-component icosahedral quasicrystals is evaluated using various simple connected acceptance volumes. Analytic forms for structure factors and pair probabilities are used both spherical polyhedral maximum value quasicrystal a volume 1.623, three-dimensional Penrose tiling it 1.655. volumes that give highest hard-sphere packing fractions subsets this at scales. best convex ones either an icosahedron or intersection...
The lowest-energy structures associated with a commonly used effective metallic pair potential are found for wide range of values the three parameters required by potential. tested include most lattices favored elements, Bravais variable c/a and b/a ratios, number candidate three-dimensional one-component quasicrystal structures. One quasicrystals is stable structure region parameter space close to virtual-crystal appropriate observed simple-metal quasicrystals. Energies also evaluated some...
A recently advanced argument against the atmospheric greenhouse effect is refuted. planet without an infrared absorbing atmosphere mathematically constrained to have average temperature less than or equal effective radiating temperature. Observed parameters for Earth prove that absorption by atmosphere, of Earth's surface would be at least 33 K lower what observed.
In this journal, Gerhard Gerlich and Ralf D. Tscheuschner claim to have falsified the existence of an atmospheric greenhouse effect. 1 Here, we show that their methods, logic, conclusions are in error. Their most significant errors include trying apply Clausius statement Second Law Thermodynamics only one side a heat transfer process rather than entire process, systematically ignoring non-radiative flows applicable Earth's surface atmosphere. They radiative from colder atmosphere warmer is...
In a recent paper, the equation of motion for complex order parameter Landau-Ginzburg Hamiltonian first- and second-order phase transitions was derived. Several special solutions this nonlinear Schr\"odinger were obtained which correspond to zero value integration constant involve restriction on carrier velocity. present we systematically analyze its in obtain complete set propagating solutions. We classify all types order-parameter envelopes find among them both localized periodic The...
This short article provides operational guidance on implementing scholarly data citation and deposition, in conformance with the Joint Declaration of Data Citation Principles (JDDCP, http://force11.org/datacitation) to help achieve widespread, uniform human machine accessibility deposited data. The JDDCP is outcome a cross-domain effort establish core principles around cited publications. It deals important issues identification, description, accessibility, persistence, evidential status...
Charge transfer in stage-1 and stage-2 Rb graphite intercalation compounds was analyzed terms of total electron-density distributions. The net charge decomposed into geometrical ``physical'' components, obtained by the integration reference difference densities [${\mathit{n}}_{\mathrm{ref}}$(r) \ensuremath{\delta}n(r)=n(r)-${\mathit{n}}_{\mathrm{ref}}$(r)], respectively, over regions associated with host or intercalant. density is superposition for intercalant sublattices treated separately,...