Extensions of the Pseudo-Potential Method

2018 ◽  
Author(s):  
Sauro Succi
Keyword(s):  
Potential Method ◽  
Original Model ◽  
Original Formulation ◽  
The Face ◽  
Pseudo Potential

This chapter provides an account of subsequent extensions of the Shan-Chen pseudo-potential method, including more elaborated potentials which extend beyond the first Brillouin cell. These extensions permit us to lift a number of limitations of the original model and considerably expand its scope and range of applications. In Chapter 27, a variety of LB techniques for nonideal fluids have been discussed. As usual, each method comes with its ups and downs, but actual evidence shows that the Shan–Chen (SC) model has enjoyed increasing popularity over the years. Interestingly, such popularity stands in the face of a fair amount of substantial criticism. In this chapter, first the Shan–Chen model is revisited in some more detail along with a discussion of ways out of the above criticism. Subsequently, the extension of the SC technique to the case of multi-range potentials extending beyond the first Brillouin cell is discussed. This extension proves pretty effective in softening many of the weaknesses of the original formulation, thereby considerably expanding its scope and range of applications.

Investigations of the Optical Properties of LaNi5 and LaNi4.5Sn0.5

2013 ◽  
Vol 321-324 ◽  
pp. 495-498 ◽  
Author(s):  
Dong Chen ◽  
Chao Xu
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Low Frequency ◽  
Potential Method ◽  
Frequency Region ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Pseudo Potential

The reflectivity, loss function, refractive index, extinction coefficient and dielectric function of the LaNi5and LaNi4.5Sn0.5intermetallic compounds are investigated through the plane-wave pseudo-potential method based on the density functional theory. The effects of Sn impurity are discussed and some interesting features are found in the low frequency region. Some important optical properties such as static dielectric constant and static refractive index are obtained. The equation [n (0)]2=ε1(0)is satisfied according to our calculation, which indicates that our results are correct and reasonable. Nevertheless, the calculated results need to be testified in the future due to the lack of experimental data.

scholarly journals El post-cognitivismo en cuestión: extensión, corporización y enactivismo

2016 ◽  
Vol 19 (3) ◽  
pp. 475
Author(s):  
Federico Gabriel Burdman
Keyword(s):  
Extended Mind ◽  
Theoretical Framework ◽  
Original Formulation ◽  
Embodied Mind ◽  
The Face

http://dx.doi.org/10.5007/1808-1711.2015v19n3p475In this paper I look into a problem concerning the characterization of the main conceptual commitments of the ‘post-cognitivist’ theoretical framework. I will firs consider critically a proposal put forth by Rowlands (2010), which identifie the theoretical nucleus of post-cognitivism with a convergence of the theses of the extended and the embodied mind. The shortcomings I fin in this proposal will lead me to an indepedent and wider issue concerning the apparent tensions between functionalism and the embodied and enactive approaches. I will then discuss the standing of embodied, enactive and extended approaches in the face of the dividing issue concerning functionalism, with an eye on the possibility of divorcing the thesis of the extended mind of its original formulation in functionalist terms. In this way, I shall consider the outlook of overcoming some of the conceptual tensions in post-cognitivism by thinking its theoretical framework as non-functionalist.

Study on Electronic Structure of GaN under Pressure

2014 ◽  
Vol 900 ◽  
pp. 217-221
Author(s):  
Xing Xiang Ruan ◽  
Xian Hui Zhong ◽  
Fu Chun Zhang ◽  
Wei Hu Zhang
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Energy Gap ◽  
Potential Method ◽  
High Energy ◽  
Functional Theory ◽  
Conduction Bands ◽  
The Density Functional Theory ◽  
The Relationship ◽  
Pseudo Potential

A detailed theoretical study of electronic structure and optical properties of GaN under pressure was performed by the first-principles calculations of plane wave ultra-soft pseudo-potential method based on the density functional theory (DFT). The results indicate that Ga-N bond length becomes shorter and the valence bonds shift towards the low energy while the conduction bands towards high energy, the band gap becomes wider with the pressure increasing, and theoretical studies explained the relationship between the band edges, energy gap of GaN and pressure. In addition, the peak in band was cracked slightly, and the Ga 3d-N 2p hybridization was enhanced.

A calculation of the phonon frequencies in sodium

1965 ◽  
Vol 283 (1392) ◽  
pp. 33-49 ◽  
Keyword(s):  
Phonon Scattering ◽  
Effective Interaction ◽  
Harmonic Approximation ◽  
Potential Method ◽  
Exchange Potential ◽  
Hartree Fock ◽  
Screened Exchange ◽  
Effective Attraction ◽  
Comparison Of The Results ◽  
Pseudo Potential

The phonon spectrum of sodium is calculated in the harmonic approximation. The effective interaction between the ions is separated into direct two-body forces between bare ions and effective attraction due to the presence of conduction electrons. Careful treatment of the two-phonon processes includes the calculation of the electron-phonon scattering based on the pseudo-potential method and the screening effects due to the interaction between electrons by the Hartree-Fock approximation with a screened exchange potential. Comparison of the results for sodium with neutron diffraction measurements and a previous calculation by Toya shows good agreement on the whole. It is hoped that this method may be applied to some other metals.

scholarly journals Ion holes in dusty pair plasmas

2008 ◽  
Vol 74 (6) ◽  
pp. 725-731 ◽  
Author(s):  
HANS SCHAMEL
Keyword(s):  
Potential Method ◽  
Periodic Wave ◽  
Dusty Plasmas ◽  
Double Layers ◽  
Wave Form ◽  
Periodic Wave Solutions ◽  
Wave Solutions ◽  
Nonlinear Dispersion Relation ◽  
Ion Acoustic Double Layers ◽  
Pseudo Potential

AbstractThe existence of Bernstein–Greene–Kruskal (BGK)-like trapped ion modes in dusty plasmas is investigated by means of the pseudo-potential method applied to the Vlasov–Poisson system. The nonlinear dispersion relation, determining the phase velocity, and the pseudo-potential, representing the wave form and hence its spectral decomposition, are derived and analysed with respect to the effect of dust. Dust is found to diminish the region in ω, k-space, where periodic wave solutions of fast and slow mode character exist. Localized wave solutions in the form of solitary ion holes, owing their existence to the presence of dust, coexist as well, but turn into slow ion acoustic double layers in the limit of vanishing dust.

scholarly journals Future-Aware Trend Alignment for Sales Predictions

Information ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 558
Author(s):  
Yiwei Liu ◽  
Lin Feng ◽  
Bo Jin
Keyword(s):  
Original Model ◽  
Data Sets ◽  
Sales Data ◽  
Significant Challenge ◽  
Data Prediction ◽  
Decision Making System ◽  
The Face ◽  
Context Specific ◽  
Almost All ◽  
Better Than

Accurately forecasting sales is a significant challenge faced by almost all companies. In particular, most products have short lifecycles without the accumulation of historical sales data. Existing methods either fail to capture the context-specific, irregular trends or to integrate as much information as is available in the face of a data scarcity problem. To address these challenges, we propose a new model, called F-TADA, i.e., future-aware TADA, which is derived from trend alignment with dual-attention multi-task recurrent neural networks (TADA). We utilize two real-world supply chain sales data sets to verify our algorithm’s performance and effectiveness on both long and short lifecycles. The experimental results show that the accuracy of the F-TADA is better than the original model. Our model’s performance could be further improved, however, by appropriately increasing the length of the windows in the decoding stage. Finally, we develop a sales data prediction and analysis decision-making system, which can offer intelligent sales guidance to enterprises.

Pseudopotential Calculation for the Electronic Properties of TbFeO3 with Perovskite Structure

2013 ◽  
Vol 483 ◽  
pp. 124-129
Author(s):  
Jian Li
Keyword(s):  
Electronic Properties ◽  
Fermi Energy ◽  
Function Theory ◽  
Potential Method ◽  
Density Function Theory ◽  
Antiferromagnetic Structure ◽  
Ferromagnetic Structure ◽  
Perovskite Type ◽  
Pseudo Potential ◽  
Perovskite Type Structure

Electronic properties and configuration of rare-earth orthoferrites TbFeO3with perovskite-type structure was calculated using pseudo-potential method basing on density function theory. TbFeO3with ferromagnetic structure and antiferromagnetic structure are investigated. By comparing calculated values with experimental results, the antiferromagnetic structure is more stable at normal condition, and its configuration optimization results is closer to the experimental measurement. In addition, TbFeO3with antiferromagnetic structure should be a semiconductor having a band gap at the Fermi energy, while for TbFeO3with ferromagnetic structure, there is no gap at the Fermi energy.

An application of the modified pseudo-potential method to e--CO scattering

1974 ◽  
Vol 27 (5) ◽  
pp. 1121-1137 ◽  
Author(s):  
P.G. Burke ◽  
N. Chandra ◽  
F.A. Gianturco
Keyword(s):  
Potential Method ◽  
Pseudo Potential
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