Results 211 to 220 of about 171,744 (267)

Band calculation of lonsdaleite Ge

Journal of Physics D: Applied Physics, 2016
Abstract The band structure of Ge in the lonsdaleite phase is calculated using first principles. Lonsdaleite Ge has a direct band gap at the Γ point. For the conduction band, the Γ valley is anisotropic with the low transverse effective mass on the hexagonal plane and the large longitudinal effective mass along ...
Pin-Shiang Chen, Sheng-Ting Fan, Huang-Siang Lan, Chee Wee Liu   +3 more
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Calculations on the Band Structure of Silicon

Proceedings of the Physical Society. Section A, 1956
The electronic band structure of silicon has been calculated along two axes of momentum space. The results agree qualitatively with experiment, but quantitative values are distorted by uncertainties in the potential used. The variational cellular method used is not too laborious in application, but appears to suffer from unexpected disadvantages at low-
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Orbital effect on a band calculation

Journal of Physics F: Metal Physics, 1977
The orbital effect is investigated by the tight-binding method, using one-electron Hartree-Fock potentials. Two simple models are considered, the first consists of a BCC lattice with five orbitals and three electrons per atom, and the second consists of an FCT lattice with three d epsilon states and two electrons per atom. In both cases, when U0/ Delta
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Empirical Band Calculations

1972
Much has been said in the very recent past about philosophy and technique of the pseudopotential method, which we regard to be the fundamental method in the area of empirical band calculations. Authoritative writers like Marvin Cohen, Volker Heine, J. C.
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Calculation of the integrated band intensities of NO

Journal of Quantitative Spectroscopy and Radiative Transfer, 1971
Abstract The integrated intensities for the 5.3-μ fundamental vibration-rotation band and for the first and second overtone bands of NO have been calculated within a quantum-mechanical framework. The dipole moment of NO was determined over a wide range of internuclear separations as an expectation value calculated with an accurate configuration ...
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Band calculations on ferroelectric crystals

Ferroelectrics, 1977
Abstract Energy bands of crystalline solids are determined using the Euwema PWG method with the Xα approximation. Here wave functions, potentials, and charge densities are expanded in a basis set of even tempered non-overlapping gaussians and plane waves. Assuming that the boundaries of molecules in a crystal are given by minimum charge density surface
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Calculating photonic band structure

Journal of Physics: Condensed Matter, 1996
Photonic materials structured on the scale of the wavelength of light have become the subject of an active field of research fed by the hope of creating novel properties. Theory plays a central role reinforced by the difficulty of manufacturing photonic materials: unusually we are better able to design a photonic material than to build it.
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Relativistic band structure calculations

International Journal of Quantum Chemistry, 1984
AbstractThe inclusion of relativistic effects in band theory is discussed. Examples showing how these affect optical properties, Fermi surface properties, and cohesive properties are shown. With respect to the latter, it is pointed out that the mass–velocity and Darwin shifts are most important, whereas the SO coupling can be omitted since it does not ...
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Solution of symmetric and unsymmetric band equations and the calculation of eigenvectors of band matrices

Numerische Mathematik, 1967
In an earlier paper in this series [2] the triangular factorization of positive definite band matrices was discussed. With such matrices there is no need for pivoting, but with non-positive definite or unsymmetric matrices pivoting is necessary in general, otherwise severe numerical instability may result even when the matrix is well-conditioned.
Martin, R. S., Wilkinson, J. H.
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Band structure calculations in solids

Reports on Progress in Physics, 1960
After a brief review of the main experimental evidence on the electronic band structure of solids, the various methods for calculating band structures, either from first principles or from empiric data, are classified and critically examined. Finally the problem of the construction of the crystal potential is discussed in an elementary way.
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