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Programmable repulsive potential for tight-binding from Chen-Möbius inversion theorem

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 71-83页

作者： Jian-Gao Li Jin-Kun Tang Hong-Quan Song Gotthard Seifert Dong-Bo Zhang College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China Department of Physics Beijing Normal UniversityBeijing 100875China College of Physics and Telecommunication Engineering Zhoukou Normal UniversityZhoukou 466001China Theoretische Chemie Technische Universität DresdenDresden D-01062Germany

An accurate total energy calculation is essential in materials *** date,many tight-binding(TB)approaches based on parameterized hopping can produce electronic structures comparable to those obtained using first-principles ***,TB approaches still have limited applicability for determining material properties derived from the total *** is,the predictive power of the TB total energy is impaired by an inaccurate evaluation of the repulsive *** complexity associated with the parametrization of TB repulsive potentials is the weak link in this *** this study,we propose a new method for obtaining the pairwise TB repulsive potential for crystalline materials by employing the Chen-Möbius inversion *** show that the TB-based phonon dispersions,calculated using the resulting repulsive potential,compare well with those obtained by first-principles calculations for various systems,including covalent and ionic bulk materials and twodimensional *** present approach only requires the first-principles total energy and TB electronic band energy as input and does not involve any *** striking feature enables us to generate repulsive potentials programmatically.

关键词： tight binding first-principles calculation total energy repulsive potential phonon dispersion

Accurate calculations of the helium atom in magnetic fields

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Chinese Physics B 2010年第11期19卷 256-263页

作者：赵继军王晓峰乔豪学 Department of Physics Wuhan University

The 1^10^＋ 1^1（-1）^＋and 1^1（2）^＋ states of the helium atom in the magnetic field regime between 0 and 100 a.u. are studied using a full configuration-interaction （CI） approach. The total energies, derivatives of the total energy with respect to the magnetic field and ionisation energies are calculated with Hylleraas-like functions in spherical coordinates in low to intermediate fields and Hylleraas Caussian functions in cylindrical coordinates in intermediate to high fields, respectively. In intermediate fields, the total energies and ionisation energies are determined in terms of Hermite interpolation, based on the results obtained with the two above-mentioned basis functions. Calculations show that the current method can produce lower total energies and larger ionisation energies, and make the two ionisation energy curves obtained with the two above-mentioned basis functions join smoothly in intermediate fields. Comparisons are also made with previous works.

关键词： strong magnetic field helium atom total energy ionisation energy

Absolute Gap of Two-Dimensional Fractal Photonic Structure

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Chinese Physics Letters 2003年第10期20卷 1767-1769页

作者：李梁谢诒成王义全胡小永冯志芳程丙英 CollegeofAppliedMathematicsandPhysics BeijingUniversityofTechnologyBeijing100022 OpticalPhysicsLaboratory InstituteofPhysicsandCenterforCondensedMatterPhysicsChineseAcademyofSciencesBeijing100080

We propose a model for two-dimensional photonic materials constructed on a kind of fractal structures. total energy flows of the photonic materials constructed with either dielectric cylinders or air holes show that b... 详细信息

关键词： total energy airhole photonic materials Fractals photonic electromagnetic waves

High accuracy calculation of the hydrogen negative ion in strong magnetic fields

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Chinese Physics B 2011年第5期20卷 222-226页

作者：赵继军王晓峰乔豪学 Department of Physics Wuhan University

Using a full configuration-interaction method with Hylleraas-Gaussian basis function, this paper investigates the 1^10^＋, 1^1（-1）^＋ and 1^1（-2）6＋ states of the hydrogen negative ion in strong magnetic fields. The total energies, electron detachment energies and derivatives of the total energy with respect to the magnetic field are presented as functions of magnetic field over a wide range of field strengths. Compared with the available theoretical data, the accuracy for the energies is enhanced significantly. The field regimes 3 〈 γ 〈 4 and 0.02 〈 γ 〈 0.05, in which the 1^1（-1）6＋ and 1^1（-2）^＋ states start to become bound, respectively, are also determined based on the calculated electron detachment energies.

关键词： strong magnetic field hydrogen negative ion total energy electron detachment energy

SELF-CONSISTENT total ENERGIES AND ELECTRONIC STRUCTURES OF HYDROGENIZED Ni,Al AND Ni_3Al

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Acta Metallurgica Sinica(English Letters) 1994年第3期7卷 220-228页

作者： XIE Qian, CHEN NanxianUniversity of Science and Technology Beijing. Beijing, China Beijing Univ of Science and Technology Beijing China

By use of the self-consistent method of linear muffin-tin orbitals with the atomic sphere approximation on the basis of density functional theory, the total energies and the electron-ic sTructures ofNi, Al, and their hydrides NiH. A1H and Ni3AlH are calculated. The theoretical excess energies and the lattice strains due to hydrogen absorption consequently obtained from the ah initio results indicate that Ni is a better hydrogen absorber than Al, an. the absorptivity of Ni3Al dramatically decreases owing to the repulsion between Al and H On the other hand, the changes of band structures due to hydrogenation are found to be remparkable except that tor Al. and they are shown to be the qualitative manifestation of existing conclusions from photoemission experiments.

关键词： total energy electronic structure hydrogenized Ni. Ai. Ni3Al

Some Properties of Si,Ge,and α-Sn Using Pseudopotential Theory

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Communications in Theoretical Physics 2010年第9期54卷 573-577页

作者： P.S.Vyas B.Y.Thakore P.N.Gajjar A.R.Jani Department of Physics Sardar Patel University Department of Physics University School of SciencesGujarat University

The pseudopotential theory beyond second order with our well established single parametric model potential is employed to compute total crystal energy, static bulk modulus, energy band gap at the point X on the Jones-zone face and pressure-volume relation （equation of state under pressure） of Si, Ge and α-Sn using Nagy＇s static local field correction function. The results are compared with those obtained using few other local field correction functions. The present results of total energy are in good agreement with the experimental data. Bulk modulus calculated by Nagy＇s screening function is perfectly matching with the experimental results for Ge and α-Sn. Some deviation is found in the value of energy band gap.

关键词： pseudopotential total energy semiconductor bulk modulus

Calculations energy of the (nl2) 1LπDoubly Excited States of Two-Electron Systems via the Screening Constant by Unit Nuclear Charge Formalism

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Journal of Modern Physics 2020年第11期11卷 1891-1910页

作者： Momar Talla Gning Ibrahima Sakho Malick Sow Department of Experimental Sciences UFR Sciences and Technologies University of Thies Thies Senegal Atoms Laser Laboratory Department of Physics Faculty of Sciences and Technologies University Cheikh Anta Diop Dakar Senegal

In this work, the total energies of doubly excited states (ns2) 1Se, (np2) 1De, (nd2) 1Ge, (nf2) 1Ie, (ng2) 1Ke, and (nh2) 1Me of the helium isoelectronic sequence with Z ≤ 10 are calculated in the framework of the variational method of the Screening Constant by Unit Nuclear Charge (SCUNC). These calculations are performed using a new wavefunction correlated to Hylleraas-type. The possibility of using the SCUNC method in the investigation of high-lying Doubly Excited States(DES) in two-electron systems is demonstrated in the present work in the case of the (nl2) 1Lπ doubly excited states, where accurate total energies are tabulated up to n = 20. All the results obtained in this paper are in agreement with the values of the available literature and may be useful for future experimental and theoretical studies on the doubly excited (nl2) 1Lπ states of two-electron systems.

关键词： Doubly Excited States Helium-Like Systems Screening Constant by Unit Nuclear Charge (SCUNC) Wave Functions Correlated total energy

Assessing Cleaner energy Alternatives for Bus Transit in Rio de Janeiro:A Life Cycle Inventory Analysis

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Journal of Environmental Protection 2015年第11期6卷 1197-1218页

作者： Marcio de Almeida D’Agosto Cintia Machado de Oliveira Fabiana do Couto Assumpcao Ana Carolina Peixoto Deveza Programa de Engenharia de Transportes Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa em Engenharia(COPPE)Universidade Federal do Rio de JaneiroRio de JaneiroBrazil Centro Federal de Educacao Tecnologica Celso Suckow da Fonseca Engenharia Industrial MecanicaUnedItaguaiBrazil

From 2003 to 2009 in Brazilian municipalities of over 60,000 inhabitants, buses accounted for more than 25% of urban trips. This trend is not expected to change in the medium term. Worldwide, buses rely on petroleum diesel as fuel. In Brazil, alternative fuels such as biodiesel, natural gas and ethanol are available and the choice among them should depend on the assessment of the entire life cycle of such fuels. This paper uses a Life Cycle Inventory, which is essential to the implementation of a Life Cycle Assessment, to assess six energy alternatives: petroleum diesel, biodiesel, petroleum diesel with 5% of biodiesel, compressed natural gas, additivated hydrous ethanol and dual-fuel system composed by petroleum diesel with 5% of biodiesel and compressed natural gas. In saving total energy consumption, pure petroleum diesel or mixed with 5% biodiesel and dual-fuel systems stand out, in that order. If renewable energy use and net carbon dioxide emissions reduction are the goals, ethanol and biodiesel should be given preference. The addition of 5% of biodiesel in petroleum diesel increases the share of renewable energy in the supply chain of petroleum diesel by 47.5% with an increase of 0.58% in total energy consumption and a reduction of 3.8% in net CO2 emissions during the life cycle. In the case of biodiesel, the addition of 5% of biodiesel in petroleum diesel increases the share of renewable energy in the supply chain by 51.15% with an increase of 0.03% in the total energy consumption and a decrease of 7% in net CO2 emissions in the life cycle. The use of 5% of biodiesel in petroleum diesel does not significantly affect the use of renewable energy (+0.69%) or total energy consumption (+0.04%) in ethanol supply chain, which already shows a great use of renewable energy input. However, a decrease of 9.29% in the net CO2 emissions in the supply chain occurs, which reaches 5.28% in the life cycle.

关键词： Renewable energy total energy Public Transportation Biofuels Life Cycle

Ground State, Isoelectronic Ions and Low-Lying Excited States of Lithium Atom in Strong Magnetic Field

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Open Journal of Microphysics 2021年第3期11卷 37-51页

作者： Khadija Abdelhassan Kharroube Mathematics Department Faculty of Science Lebanese University Beirut Lebanon

In the framework of the variational Monte Carlo method, the ground states of the lithium atom and lithium like ions up to Z = 10 in an external strong magnetic field are evaluated. Furthermore, the two low-lying excit... 详细信息

Variational Monte Carlo Method Atoms in Magnetic Field Ground States of Li Binding energy total energy