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Optimized numerical density functional theory calculation of rotationally symmetric jellium model systems

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Chinese Physics B 2024年第10期33卷 349-355页

作者： Guangdi Zhang Li Mao Hongxing Xu School of Physics and Technology Wuhan UniversityWuhan 430070China Wuhan Institute of Quantum Technology Wuhan 430205China School of Microelectronics Wuhan UniversityWuhan 430072China Henan Academy of Sciences Zhengzhou 450046China

In real space density functional theory calculations,the effective potential depends on the electron density,requiring self-consistent iterations,and numerous integrals at each step,making the process *** our research,we propose an optimization method to expedite density functional theory(DFT)calculations for systems with large aspect ratios,such as metallic nanorods,nanowires,or scanning tunneling microscope *** method focuses on employing basis set to expand the electron density,Coulomb potential,and exchange-correlation *** precomputing integrals and caching redundant results,this expansion streamlines the integration process,significantly accelerating DFT *** a case study,we have applied this optimization to metallic nanorod systems of various radii and lengths,obtaining corresponding ground-state electron densities and potentials.

关键词： density functional theory basis set integrals precomputation nanorod

Density Functional Method Studies of X H （X=C, N, O, Si, P, S） Bond Dissociation Energies

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Chinese Journal of Chemistry 2005年第5期23卷 474-482页

作者：傅尧董晓昱王毅敏刘磊郭庆祥 DepartmentofChemistry UniversityofScienceandTechnologyofChinaHefeiAnhui230026

The performances of the density functional theory (DFT) methods in calculating X  H bond dissociation energies (BDE, XC, N, O, Si, P, S) were evaluated. It was found that most DFT methods including B3LYP, B3PW91, G96LYP, PBE1PBE and BH&HLYP significantly underestimated the X  H BDE by as much as 13–24 kJ/mol. The underestimation is not due to the use of finite basis set, because the DFT methods still significantly underestimate the X  H BDE with the complete basis set. Therefore, these DFT methods can not be used to calculate the BDE directly. Nevertheless, the B3P86 method shows very small underestimation for the X  H BDE. Further analysis suggests that there be no advantage for using the restricted open‐shell DFT methods. The unrestricted DFT methods actually perform slightly better than the restricted open‐shell DFT methods in most cases. Finally, it was found that the underestimation by the DFT methods was largely systematic. The use of the calibrated UDFT/6‐311++G(d, p) method was recommended to calculate the X  H BDE.

关键词： density functional theory bond dissociation energy basis set B3P86 method

Solutions of the 1D Coupled Nonlinear Schrodinger Equations by the CIP-BS Method

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Communications in Computational Physics 2006年第2期1卷 261-275页

作者： Takayuki Utsumi Takayuki Aoki James Koga Mitsuru Yamagiwa Department of Electronics and Computer Science Tokyo University of ScienceYamaguchi1-1 Daigaku-doriSanyou-OnodaYamaguchi 756-0884Japan Global Scientific Information and Computing Center Tokyo Institute of TechnologyO-okayamaMeguro-kuTokyo 152-8552Japan Japan Atomic Energy Agency 8-1 Umemidai Kizu-choSouraku-gunKyoto 619-0215Japan

In this paper,we present solutions for the one-dimensional coupled nonlinear Schrödinger(CNLS)equations by the Constrained Interpolation Profile-basis set(CIP-BS)*** method uses a simple polynomial basis set,by which physical quantities are approximated with their values and derivatives associated with grid *** operations on functions are carried out in the framework of differential ***,by introducing scalar products and requiring the residue to be orthogonal to the basis,the linear and nonlinear partial differential equations are reduced to ordinary differential equations for values and spatial *** method gives stable,less diffusive,and accurate results for the CNLS equations.

关键词： The CIP-BS method basis set differential algebra the Galerkin method the coupled nonlinear Schrödinger equation

THE THEORETICAL STUDY OF ADSORPTION OF METAL IONS ON CHITOSAN

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Chinese Journal of Reactive Polymers 2005年第1期14卷 76-81页

作者： LU Renqing ZHANG Hongyu QIU Guangmin LIU Chenguang College of Chemistry and Chemical Engineering China University of Petroleum （East China） Dongying 257061 China Environmental Sanitation Office Municipal AdministrationYantai Economic and Technological Developmental Zone Yantai 264000 China College of Petroleum Engineering China University of Petroleum （East China） Dongying 257061 China

The interactions between metal ions such as Zn2+, Pb2+, Mn2+, Hg2+, Cd2+, Ni2+ and chitosan have been investigated using the model cluster model method and density functional method. Full optimization and frequency analysis of all cluster models have been performed employing B3LYP hybrid method at 3-21G basis set level except metal ions which were invoked to use effective core potential (ECP) method. The energy changes, and the main structural parameters have been obtained during the theoretical study of the adsorption of metal ions on the chitosan. The calculations showed that the coordination modes of metal ions with chitosan models were different, the geometries of Mn2+, Zn2+, Cd2+, Hg2+, Pb2+ ions coordinated with two nitrogen atoms and two oxygen atoms were distorted tetrahedral, while the square planar structure of Ni2+ coordinated two nitrogen atoms and two oxygen atoms was observed. The heat of reaction between six metal ions and chitosan models showed the order: Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+, this suggested that the coordination strength of Mn2+ >Ni2+ >Zn2+ >Pb2+ >Hg2+ >Cd2+.

关键词： Density functional theory basis set Effective core potential Chitosan, Metal ions.

THE THEORETICAL STUDY OF ADSORPTION OF METAL IONS ON CHITOSAN

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Chinese Journal of Reactive Polymers 2005年第Z1期 76-81页

作者： Lü Renqing1 ZHANG Hongyu2 QIU Guangmin3 LIU Chenguang1 1 College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Dongying 257061, China 2 Environmental Sanitation Office, Municipal Administration, Yantai Economic and Technological Developmental Zone, Yantai 264000, China 3 College of Petroleum Engineering, China University of Petroleum (East China), Dongying 257061, China

关键词： Density functional theory basis set Effective core potential Chitosan, Metal ions.

DFT Studies of Mo-C Heterocyclic Rings

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有机化学 2003年第Z1期23卷 238-238页

作者： RAN Xiao-Rong ZHAO Hai-Tao ZHANG Wen-Qin Department of Chemistry Tianjin University Tianjin 300072 Department of Chemistry Tianjin University Tianjin 300072 Department of Chemistry Tianjin University Tianjin 300072

　　Eleven clusters of the six-membered Mo-C heterocyclic rings were calculated and compared with corresponding organic compounds. The structure, stability and the electronic properties of these clusters are discussed. All calcu- lations were carried out within the framework of the density functional theory (DFT) with a plane wave basis set, which encoded in VASP (Vienna Ab-initio Simulation Package). [1,2]……

关键词： density functional theory electronic properties organic compounds basis set