Results 211 to 220 of about 3,650 (244)
Higher-order perturbative relativistic calculations for few-electron atoms and ions
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2017 Abstract An effective computational method is developed for electronic-structure calculations in few-electron atoms and ions on the basis of the Dirac-Coulomb-Breit Hamiltonian. The recursive formulation of the perturbation theory provides an efficient access to the higher-order contributions of the interelectronic interaction.
D. A. Glazov +5 more
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Higher order perturbation calculation with higher mode eigenfunctions in homogeneous system
Annals of Nuclear Energy, 2000Abstract By introducing two perturbed systems from a homogeneous core the higher order perturbation calculation of a heterogeneous core was performed to obtain the neutron flux and reactivity change with the higher mode eigenfunctions in the homogeneous core system which is considered to be an unperturbed system. The main feature of this perturbation
Cheol Ho Pyeon +3 more
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Full finite perturbation calculations of NMR screening constants and higher order effects
Journal of Molecular Structure: THEOCHEM, 1988Abstract A finite-perturbation calculation method of the possibly field-dependent nuclear magnetic shielding in NMR experiments at very high field is presented. Numerical results obtained on the H− ion are given.
A. Boucekkine +3 more
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The calculation of higher-order energies in the many-body perturbation theory series
Chemical Physics Letters, 1985Abstract Perturbation energies through 8th order, have been calculated for the molecules H 2 O, CH 2 , BH and Be 2 using a variety of basis sets. The purpose of these calculations is to examine the errors involved in the usual truncation of the series at 4th or lower order as in standard many-body perturbation theory or Moller—Plesset calculations ...
P.J. Knowles +3 more
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Higher Order Perturbation Method in Reactor Calculations
Nuclear Science and Engineering, 1973AbstractA higher order perturbation formula for calculating changes in the reactivity up to a desired order in concise form is given; the formula uses the iterative technique well known in quantum mechanics and in the neutron life-cycle method. This procedure is possible only when the adjoint flux in the unperturbed system is used as the weighting ...
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Volume 6: Beyond Design Basis Events; Student Paper Competition, 2013
The role of scientific computing has been heavily promoted in many fields to improve understanding the physics of complex engineering systems in recent years while conduct the experiments can be time-consuming, inflexible, expensive and difficult to repeat, e.g. nuclear reactor systems.
Congjian Wang, Hany S. Abdel-Khalik
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The role of scientific computing has been heavily promoted in many fields to improve understanding the physics of complex engineering systems in recent years while conduct the experiments can be time-consuming, inflexible, expensive and difficult to repeat, e.g. nuclear reactor systems.
Congjian Wang, Hany S. Abdel-Khalik
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Use of continued fractions for the calculation of higher-order terms in a perturbation system
Chemical Physics Letters, 1981Abstract Higher-order terms of eigenvalues in a perturbation system with discrete energy levels described by the Schrodinger equation are calculated using continued fractions. This method is used for calculating energy eigenvalues for a rigid rotator which has a dipole and interacts with an applied electric field.
Akio Morita, Hiroshi Watanabe
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Optics & Laser Technology, 2005
We present an efficient algorithm for determining mode eigenvalues as well as field distributions of optical waveguides with two-dimensional transverse refractive index profile. The algorithm is devised with the analytical perturbation correction method combined with the finite difference approximation of Helmoltz's equation.
Partha Roy Chaudhuri +3 more
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We present an efficient algorithm for determining mode eigenvalues as well as field distributions of optical waveguides with two-dimensional transverse refractive index profile. The algorithm is devised with the analytical perturbation correction method combined with the finite difference approximation of Helmoltz's equation.
Partha Roy Chaudhuri +3 more
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A perturbation method suitable for higher order calculations
Journal of Molecular Spectroscopy, 1965Abstract A form of perturbation theory is described which is particularly useful for the calculation of the higher order corrections. In technique of application, the method is intermediate to the usual Rayleigh-Schrodinger method and the contact transformation technique of Van Vleck, but it appears to be more appropriate than either for a number of ...
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Calculation of the higher-order perturbations in the theory of gamma transport
Soviet Physics Journal, 1968The higher-order perturbations in the application of perturbation theory to the γ-transport equation are discussed. An analytic expression is obtained for the perturbation flux of arbitrary order arising from a variation in the electron density of the medium, regardless of its geometry.
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