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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

THE RELATIVISTIC pseudopotential MCSCF CALCULATIONS FOR SOME LOW-LYING STATES OF TiCI_2

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Chinese Science Bulletin 1990年第14期35卷 1186-1188页

作者：马忠新戴树珊 Department of Chemistry Yunnan University Kunming 650091 PRC

The fragments such as TiCl2 are encountered in the study of the reaction mechanism about organometallic complexes and clusters. It is of significanoce to study the metastables for the investigation of the reaction mechanism and the synthesis of a new type of clusters and organometallic complexes. Hoffmann and his co-workers developed isolobal analogue theory and proved it by using EHMO and other qualitative methods. However, in

关键词： ab initio MCSCF relativistic pseudopotential near-degenerate.

Relativistic pseudopotential CI ab initio Calculations on the Low-lying States of XeH

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Chinese Science Bulletin 1994年第4期39卷 283-287页

作者：涂学炎戴树珊 Department of Chemistry Yunnan University Kunming 650091 PRC

RgH (Rg represents the rare gases) molecules are different from the commonhydrides, becasue its ground state is repulsive, but its excited state is bound. So it isexpected to be used as the producer of laser, of which... 详细信息

关键词： relativistic pseudopotential CI XeH.

Modeling for Collapsing Cavitation Bubble near Rough Solid Wall by Mulit-Relaxation-Time pseudopotential Lattice Boltzmann Model

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Journal of Applied Mathematics and Physics 2017年第6期5卷 1243-1256页

作者： Minglei Shan Yipeng Zhu Cheng Yao Qingbang Han Changping Zhu College of Internet of Things Engineering Hohai University Changzhou China Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Hohai University Changzhou China

Cavitation bubble collapse near rough solid wall is modeled by the multi-relaxation-time (MRT) pseudopotential lattice Boltzmann (LB) model. The modified forcing scheme, which can achieve LB model’s thermodynamic consistency by tuning a parameter related with the particle interaction range, is adopted to achieve desired stability and density ratio. The bubble collapse near rough solid wall was simulated by the improved MRT pseudopotential LB model. The mechanism of bubble collapse is studied by investigating the bubble profiles, pressure field and velocity field evolution. The eroding effects of collapsing bubble are analyzed in details. It is found that the process and the effect of the interaction between bubble collapse and rough solid wall are affected seriously by the geometry of solid boundary. At the same time, it demonstrates that the MRT pseudopotential LB model is a potential tool for the investigation of the interaction mechanism between the collapsing bubble and complex geometry boundary.

关键词： Cavitation Bubble Bubble Collapse Lattice Boltzmann Method pseudopotential Model Rough Solid Wall

Study on H atoms diffusion and adsorption properties of MgH_2-V systems

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Science China(Technological Sciences) 2008年第7期51卷 979-988页

作者： ZHOU DianWu1,2, LIU JinShui3 & PENG Ping3 1 State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China 2 College of Mechanical and Automatic Engineering, Hunan University, Changsha 410082, China 3 College of Materials Science and Engineering, Hunan University, Changsha 410082, China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha China College of Mechanical and Automatic Engineering Hunan University Changsha China College of Materials Science and Engineering Hunan University Changsha China

Based on experimental results that VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at.%V nanocomposite, H atoms diffusion and adsorption properties of MgH2-V systems have been investigated by using a first-principles plane-wave pseudopotential method based on the density functional theory. The results are as follows. When VH/MgH2 interface is formed due to V alloying MgH2 phase, the vacancy formed by H atoms near VH phase region is more stable than that without V alloying, while vacancy near MgH2 phase region is less stable than that without V alloying. During the process of H atoms diffusion after V alloying, the max migration barrier energy of H atoms in MgH2-V systems is reduced compared with that of MgH2 phase, which means that H atoms diffuse easily. When H diffuses into VH from MgH2 across VH/MgH2 interface, among three substitutions such as the replacement of H for V vacancy, or interstitial site or V atoms, the replacement of H for V vacancy has the strongest diffusion ability, next interstitial site, and finally V atoms site. As far as H adsorbed on different surfaces of VH phase is concerned, physical adsorption is carried out more easily than chemical adsorption, and the behavior of H atoms adsorbed on the surface near VH phase region can be found more easily than that near MgH2 phase region.

关键词： plane-wave pseudopotential theory magnesium hydride diffusion adsorption

Structure of Some 4f Rare Earth Liquid Metals --A Charged Hard Sphere Approach

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Communications in Theoretical Physics 2006年第2X期46卷 337-342页

作者： P.B. Thakor P.N. Gajjar A.R. Jani Department of Physics Veer Nazmad South Gujarat University Udhana Magdalla Road Surat 395 007 Gujarat India Department of Physics Oujarat University Ahmedabd Oujarat India Department of Physics Sardar Patel University Vallabh Vidyanagar 388 120 Gujarat India

A well-established pseodopotential is used to study the structure of some 4f rare earth liquid metals （Ce, Pr, Eu, Gd, Tb, and Yb）. The structure factor S（q）, pair distribution function g（r）, interatomic distance r1, and coordination number n1 are calculated using Charged Hard Sphere （CHS） reference system. To introduce the exchange and correlation effects, the local field correction due to Sarkar et al. （S） is applied. The present investigation is successful in generating the structural information of Ce, Pr, Eu, Gd, Tb, and Yb 4f rare earth liquid metals.

关键词： pseudopotential structure factor pair distribution function interatomic distance

Electron Dispersion in Liquid Alkali and Their Alloys

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Communications in Theoretical Physics 2010年第7期54卷 159-166页

作者： Aditya M.Vora Humanities and Social Science Department S.T.B.S.College of Diploma Engineering

Ashcroft＇s local empty core （EMC） model pseudopotential in the second-order perturbation theory is used to study the electron dispersion relation, the Fermi energy, and deviation in the Fermi energy from free electron value for the liquid alkali metals and their equiatomic binary alloys for the first time. In the present computation, the use of pseudo-alloy-atom model （PAA） is proposed and found successful. The influence of the six different forms of the local field correction functions proposed by Hartree （H）, Vashishta Singwi （VS）, Taylor （T）, lehimaru-Utsumi （IU）, Farid et al. （F）, and Sarkar et al. （S） on the aforesaid electronic properties is examined explicitly, which reflects the varying effects of screening. The depth of the negative hump in the electron dispersion of liquid alkalis decreases in the order Li --→ K, except for Rb and Cs, it increases. The results of alloys are in predictive nature.

关键词： pseudopotential Fermi energy electron dispersion curves local field correction functions alkalimetals and their alloys

Molecular structure of diatomic lanthanide compounds

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Science China Chemistry 2002年第1期45卷 91-96页

作者：曹晓燕刘文剑 MichaelDolg Institut für Physikalische & Theoretische Chemie Bonn Germany Biochemistry Department Zhongshan University Guangzhou China Lehrstuhl für Theoretische Chemie Ruhr-Universität Bochum Germany

The molecular constants of selected diatomic lanthanide compounds (LaH, LaO, LaF, EuH, EuO, EuF, EuS, GdO, GdF, GdH, YbH, YbO, YbF, YbS, LuH, LuO and LuF) have been calculated by using relativistic small-core pseudopotentials and optimized (14s13p10d8f6g)/ [6s6p5d4f3g] valence basis sets. The results are in good agreement with available experimental data, with exception of YbO and LuF. The reasons for the discrepancies in case of YbO are due to a complicated mixing of configurations in the ground state, whereas in case of LuF the binding energy estimated by experimentalists appears to be too low.

关键词： molecular structure lanthanide element pseudopotential valence basis set.

Transport Properties of Si and Ge Liquid Semiconductor Metals

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Communications in Theoretical Physics 2009年第3期51卷 550-554页

作者： Aditya M.Vora Humanities and Social Science Department S.T.B.S. College of Diploma Engineering

In the present article, we study the electrical resistivity ρ, the thermoelectric power （TEP） α, thermal conductivity σ, Knight-Shifts and temperature coefficient of the Knight-Shifts of the liquid Si and Ge using the well known model potential for the first time. The structure factor used in the present work is derived from the Percus-Yevick （PY） theory. Various local field correction functions are used to study the screening influence. The present results of resistivity are found in qualitative agreement with available experimental and theoretical whenever exists.

关键词： pseudopotential electrical resistivity thermoelectric power Knight Shift PY theory local field correction functions