Electronic structure of clusters (LiBC)_n n=1, 2, 4
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Exploring Chemistry with Electronic Structure MethodSecond EdithionJames B. ForesmanAeleen FrischGaussian, IncPittsburgh, PA2002年9月25日特别声明本文转自南开大学BBS,在此对译者表示衷心感!!!!用Gaussian研究化学问题说明接触Gaussian已经很久了,但真正用Gaussian做东西还是临近博士毕业时的事情。
当时做计算的时候,就特别希望有一本具体怎么使用从头算的书,可惜一直没有找到。
来到这里后,在新买的Gaussian98包中发现了这本书,感觉如获至宝,也希望能够提供应想用Gaussian做东西的朋友。
我不是专门做量化的,很多术语不清楚怎么翻译,手头又没有中文的资料,错误的地方,只能希望行来指点了。
其实这本书里面介绍的东西,不止限于Gaussian 程序的。
对于从事从头算研究的都有帮助。
容中有很多计算实例,都是在Gaussian94,98程序中提供的。
节译自Exploring Chemistry with Electronic Structure Methos,SecondEdition,作者James B。
Foresman,Eleen FrischGaussian,Inc,USA,1996目录特别声明1用Gaussian研究化学问题1说明1前言1运行Gaussian2Unix/Linux平台2Windows平台2输出文件2第一章计算模型31.1 计算化学概述3分子力学理论3电子结构理论4密度泛函(Density Functional Methods)41.2 化学模型(Model Chemistries)4定义化学模型4模型的组合5第二章单点能计算52.1 能量计算设置5路径5计算的名称6分子结构6多步计算62.3 输出文件中的信息6标准几何坐标。
6能量6分子轨道和轨道能级6电荷分布7偶极矩和多极矩7CPU时间和其他72.4 核磁计算7第三章几何优化93.1 势能面93.2 寻找极小值9收敛标准10几何优化的输入10检查优化输出文件103.3 寻找过渡态103.4 难处理的优化11第四章频率分析134.1 预测红外和拉曼光谱13频率计算的输入13频率和强度13矫正因子和零点能。
电子英语证书考试(PEC)-集成电路词汇汇总Abrupt junction 突变结Accelerated testing 加速实验Acceptor 受主Acceptor atom 受主原子Accumulation 积累、堆积Accumulating contact 积累接触Accumulation region 积累区Accumulation layer 积累层Active region 有源区Active component 有源元Active device 有源器件Activation 激活Activation energy 激活能Active region 有源(放大)区Admittance 导纳Allowed band 允带Alloy-junction device合金结器件Aluminum(Aluminium) 铝Aluminum – oxide 铝氧化物Aluminum passivation 铝钝化Ambipolar 双极的Ambient temperature 环境温度Amorphous 无定形的,非晶体的Amplifier 功放扩音器放大器Analogue(Analog) comparator 模拟比较器Angstrom 埃Anneal 退火Anisotropic 各向异性的Anode 阳极Arsenic (AS) 砷Auger 俄歇Auger process 俄歇过程Avalanche 雪崩Avalanche breakdown 雪崩击穿Avalanche excitation雪崩激发Background carrier 本底载流子Background doping 本底掺杂Backward 反向Backward bias 反向偏置Ballasting resistor 整流电阻Ball bond 球形键合Band 能带Band gap 能带间隙Barrier 势垒Barrier layer 势垒层Barrier width 势垒宽度Base 基极Base contact 基区接触Base stretching 基区扩展效应Base transit time 基区渡越时间Base transport efficiency基区输运系数Base-width modulation基区宽度调制Basis vector 基矢Bias 偏置Bilateral switch 双向开关Binary code 二进制代码Binary compound semiconductor 二元化合物半导体Bipolar 双极性的Bipolar Junction Transistor (BJT)双极晶体管Bloch 布洛赫Blocking band 阻挡能带Blocking contact 阻挡接触Body - centered 体心立方Body-centred cubic structure 体立心结构Boltzm ann 波尔兹曼Bond 键、键合Bonding electron 价电子Bonding pad 键合点Bootstrap circuit 自举电路Bootstrapped emitter follower 自举射极跟随器Boron 硼Borosilicate glass 硼硅玻璃Boundary condition 边界条件Bound electron 束缚电子Breadboard 模拟板、实验板Break down 击穿Break over 转折Brillouin 布里渊Brillouin zone 布里渊区Built-in 内建的Build-in electric field 内建电场Bulk 体/体内Bulk absorption 体吸收Bulk generation 体产生Bulk recombination 体复合Burn - in 老化Burn out 烧毁Buried channel 埋沟Buried diffusion region 隐埋扩散区Can 外壳Capacitance 电容Capture cross section 俘获截面 Capture carrier 俘获载流子Carrier 载流子、载波Carry bit 进位位Carry-in bit 进位输入 Carry-out bit 进位输出Cascade 级联 Case 管壳Cathode 阴极 Center 中心Ceramic 陶瓷(的)Channel 沟道Channel breakdown 沟道击穿Channel current 沟道电流Channel doping 沟道掺杂 Channel shortening 沟道缩短Channel width 沟道宽度 Characteristic impedance 特征阻抗Charge 电荷、充电 Charge-compensation effects 电荷补偿效应Charge conservation 电荷守恒 Charge neutrality condition 电中性条件Charge drive/exchange/sharing/transfer/storage 电荷驱动/交换/共享/转移/存储Chemmical etching 化学腐蚀法 Chemically-Polish 化学抛光Chemmically-Mechanically Polish (CMP) 化学机械抛光Chip 芯片Chip yield 芯片成品率Clamped 箝位Clamping diode 箝位二极管Cleavage plane 解理面Clock rate 时钟频率 Clock generator 时钟发生器Clock flip-flop 时钟触发器Close-packed structure 密堆积结构Close-loop gain 闭环增益 Collector 集电极Collision 碰撞 Compensated OP-AMP 补偿运放Common-base/collector/emitter connection 共基极/集电极/发射极连接Common-gate/drain/source connection 共栅/漏/源连接Common-mode gain 共模增益 Common-mode input 共模输入Common-mode rejection ratio (CMRR) 共模抑制比Compatibility 兼容性Compensation 补偿Compensated impurities 补偿杂质 Compensated semiconductor 补偿半导体Complementary Darlington circuit 互补达林顿电路Complementary Metal-Oxide-Semiconductor Field-Effect-Transistor(CMOS)互补金属氧化物半导体场效应晶体管Complementary error function 余误差函数Computer-aided design (CAD)/test(CAT)/manufacture(CAM) 计算机辅助设计/ 测试/制造Compound Semiconductor 化合物半导体 Conductance 电导Conduction band (edge) 导带(底) Conduction level/state 导带态Conductor 导体 Conductivity 电导率Configuration 组态 Conlomb 库仑Conpled Configuration Devices 结构组态Constants 物理常数Constant energy surface 等能面 Constant-source diffusion恒定源扩散Contact 接触Contamination 治污Continuity equation 连续性方程Contact hole 接触孔Contact potential 接触电势Continuity condition 连续性条件Contra doping 反掺杂 Controlled 受控的Converter 转换器Conveyer 传输器Copper interconnection system 铜互连系统Couping 耦合Covalent 共阶的Crossover 跨交Critical 临界的Crossunder 穿交Crucible坩埚 Crystal defect/face/orientation/lattice 晶体缺陷/晶面/晶向/晶格Current density 电流密度Curvature 曲率Cut off 截止Current drift/dirve/sharing 电流漂移/驱动/共享Current Sense 电流取样Curvature 弯曲Custom integrated circuit 定制集成电路Cylindrical 柱面的Czochralshicrystal 直立单晶Czochralski technique 切克劳斯基技术(Cz法直拉晶体J)Dangling bonds 悬挂键Dark current 暗电流Dead time 空载时间Debye length 德拜长度De.broglie 德布洛意Decderate 减速Decibel (dB) 分贝Decode 译码Deep acceptor level 深受主能级Deep donor level 深施主能级Deep impurity level 深度杂质能级Deep trap 深陷阱Defeat 缺陷Degenerate semiconductor 简并半导体Degeneracy 简并度Degradation 退化Degree Celsius(centigrade) /Kelvin 摄氏/开氏温度Delay 延迟Density 密度Density of states 态密度Depletion 耗尽Depletion approximation 耗尽近似Depletion contact 耗尽接触Depletion depth 耗尽深度Depletion effect 耗尽效应Depletion layer 耗尽层Depletion MOS 耗尽MOSDepletion region 耗尽区Deposited film 淀积薄膜Deposition process 淀积工艺Design rules 设计规则Die 芯片(复数dice)Diode 二极管Dielectric 介电的Dielectric isolation 介质隔离Difference-mode input 差模输入Differential amplifier 差分放大器Differential capacitance 微分电容Diffused junction 扩散结Diffusion 扩散Diffusion coefficient 扩散系数Diffusion constant 扩散常数Diffusivity 扩散率Diffusion capacitance/barrier/current/furnace 扩散电容/势垒/电流/炉Digital circuit 数字电路Dipole domain 偶极畴Dipole layer 偶极层Direct-coupling 直接耦合Direct-gap semiconductor 直接带隙半导体Direct transition 直接跃迁Discharge 放电Discrete component 分立元件Dissipation 耗散Distribution 分布Distributed capacitance 分布电容Distributed model 分布模型Displacement 位移Dislocation 位错Domain 畴Donor 施主Donor exhaustion 施主耗尽Dopant 掺杂剂Doped semiconductor 掺杂半导体Doping concentration 掺杂浓度Double-diffusive MOS(DMOS)双扩散MOS.Drift 漂移Drift field 漂移电场Drift mobility 迁移率Dry etching 干法腐蚀Dry/wet oxidation 干/湿法氧化Dose 剂量Duty cycle 工作周期Dual-in-line package (DIP)双列直插式封装Dynamics 动态Dynamic characteristics 动态属性Dynamic impedance 动态阻抗Early effect 厄利效应Early failure 早期失效Effective mass 有效质量Einstein relation(ship) 爱因斯坦关系Electric Erase Programmable Read Only Memory(E2PROM) 一次性电可擦除只读存储器Electrode 电极Electrominggratim 电迁移Electron affinity 电子亲和势Electronic -grade 电子能Electron-beam photo-resist exposure 光致抗蚀剂的电子束曝光Electron gas 电子气Electron-grade water 电子级纯水Electron trapping center 电子俘获中心 Electron Volt (eV) 电子伏Electrostatic 静电的Element 元素/元件/配件Elemental semiconductor 元素半导体Ellipse 椭圆Ellipsoid 椭球Emitter 发射极Emitter-coupled logic 发射极耦合逻辑Emitter-coupled pair 发射极耦合对Emitter follower 射随器Empty band 空带Emitter crowding effect 发射极集边(拥挤)效应Endurance test =life test 寿命测试 Energy state 能态Energy momentum diagram 能量-动量(E-K)图Enhancement mode 增强型模式Enhancement MOS 增强性MOS Entefic (低)共溶的Environmental test 环境测试Epitaxial 外延的Epitaxial layer 外延层Epitaxial slice 外延片Expitaxy 外延Equivalent curcuit 等效电路Equilibrium majority /minority carriers 平衡多数/少数载流子Erasable Programmable ROM (EPROM)可搽取(编程)存储器Error function complement 余误差函数Etch 刻蚀Etchant 刻蚀剂Etching mask 抗蚀剂掩模Excess carrier 过剩载流子Excitation energy 激发能 Excited state 激发态Exciton 激子 Extrapolation 外推法Extrinsic 非本征的Extrinsic semiconductor 杂质半导体Face - centered 面心立方Fall time 下降时间Fan-in 扇入Fan-out 扇出Fast recovery 快恢复F ast surface states 快界面态Feedback 反馈Fermi level 费米能级Fermi-Dirac Distribution 费米-狄拉克分布Femi potential 费米势Fick equation 菲克方程(扩散)Field effect transistor 场效应晶体管Field oxide 场氧化层Filled band 满带Film 薄膜Flash memory 闪烁存储器Flat band 平带Flat pack 扁平封装Flicker noise 闪烁(变)噪声Flip-flop toggle 触发器翻转Floating gate 浮栅Fluoride etch 氟化氢刻蚀Forbidden band 禁带Forward bias 正向偏置Forward blocking /conducting正向阻断/导通Frequency deviation noise频率漂移噪声Frequency response 频率响应Function 函数Gain 增益Gallium-Arsenide(GaAs) 砷化钾Gamy ray r 射线Gate 门、栅、控制极Gate oxide 栅氧化层Gauss(ian)高斯Gaussian distribution profile 高斯掺杂分布Generation-recombination 产生-复合Geometries 几何尺寸Germanium(Ge) 锗Graded 缓变的Graded (gradual) channel 缓变沟道Graded junction 缓变结Grain 晶粒Gradient 梯度Grown junction 生长结Guard ring 保护环Gummel-Poom model 葛谋-潘模型Gunn - effect 狄氏效应Hardened device 辐射加固器件Heat of formation 形成热Heat sink 散热器、热沉Heavy/light hole band 重/轻空穴带Heavy saturation 重掺杂Hell - effect 霍尔效应Heterojunction 异质结Heterojunction structure 异质结结构Heterojunction Bipolar Transistor(HBT)异质结双极型晶体High field property 高场特性High-performance MOS.( H-MOS)高性能MOS. Hormalized 归一化Horizontal epitaxial reactor 卧式外延反应器Hot carrior 热载流子Hybrid integration 混合集成Image - force 镜象力Impact ionization 碰撞电离Impedance 阻抗Imperfect structure 不完整结构Implantation dose 注入剂量Implanted ion 注入离子Impurity 杂质Impurity scattering 杂志散射Incremental resistance 电阻增量(微分电阻)In-contact mask 接触式掩模Indium tin oxide (ITO) 铟锡氧化物Induced channel 感应沟道Infrared 红外的Injection 注入Input offset voltage 输入失调电压Insulator 绝缘体Insulated Gate FET(IGFET)绝缘栅FET Integrated injection logic集成注入逻辑Integration 集成、积分Interconnection 互连Interconnection time delay 互连延时Interdigitated structure 交互式结构Interface 界面Interference 干涉International system of unions国际单位制Internally scattering 谷间散射Interpolation 内插法Intrinsic 本征的Intrinsic semiconductor 本征半导体Inverse operation 反向工作Inversion 反型Inverter 倒相器Ion 离子Ion beam 离子束Ion etching 离子刻蚀Ion implantation 离子注入Ionization 电离Ionization energy 电离能Irradiation 辐照Isolation land 隔离岛Isotropic 各向同性Junction FET(JFET) 结型场效应管Junction isolation 结隔离Junction spacing 结间距Junction side-wall 结侧壁Latch up 闭锁Lateral 横向的Lattice 晶格Layout 版图Lattice binding/cell/constant/defect/distortion 晶格结合力/晶胞/晶格/晶格常熟/晶格缺陷/晶格畸变Leakage current (泄)漏电流Level shifting 电平移动Life time 寿命linearity 线性度Linked bond 共价键Liquid Nitrogen 液氮Liquid-phase epitaxial growth technique 液相外延生长技术Lithography 光刻Light Emitting Diode(LED) 发光二极管Load line or Variable 负载线Locating and Wiring 布局布线Longitudinal 纵向的Logic swing 逻辑摆幅Lorentz 洛沦兹Lumped model 集总模型Majority carrier 多数载流子Mask 掩膜板,光刻板Mask level 掩模序号Mask set 掩模组Mass - action law质量守恒定律Master-slave D flip-flop主从D触发器Matching 匹配Maxwell 麦克斯韦Mean free path 平均自由程Meandered emitter junction梳状发射极结Mean time before failure (MTBF) 平均工作时间Megeto - resistance 磁阻Mesa 台面MESFET-Metal Semiconductor金属半导体FETMetallization 金属化Microelectronic technique 微电子技术Microelectronics 微电子学Millen indices 密勒指数Minority carrier 少数载流子Misfit 失配Mismatching 失配Mobile ions 可动离子Mobility 迁移率Module 模块Modulate 调制Molecular crystal分子晶体Monolithic IC 单片IC MOSFET金属氧化物半导体场效应晶体管Mos. Transistor(MOST )MOS. 晶体管Multiplication 倍增Modulator 调制Multi-chip IC 多芯片ICMulti-chip module(MCM) 多芯片模块Multiplication coefficient倍增因子Naked chip 未封装的芯片(裸片)Negative feedback 负反馈Negative resistance 负阻Nesting 套刻Negative-temperature-coefficient 负温度系数Noise margin 噪声容限Nonequilibrium 非平衡Nonrolatile 非挥发(易失)性Normally off/on 常闭/开Numerical analysis 数值分析Occupied band 满带 Officienay 功率Offset 偏移、失调On standby 待命状态Ohmic contact 欧姆接触 Open circuit 开路Operating point 工作点 Operating bias 工作偏置Operational amplifier (OPAMP)运算放大器Optical photon =photon 光子 Optical quenching光猝灭Optical transition 光跃迁 Optical-coupled isolator光耦合隔离器Organic semiconductor有机半导体 Orientation 晶向、定向Outline 外形Out-of-contact mask非接触式掩模Output characteristic 输出特性Output voltage swing 输出电压摆幅Overcompensation 过补偿 Over-current protection 过流保护Over shoot 过冲Over-voltage protection 过压保护Overlap 交迭 Overload 过载Oscillator 振荡器Oxide 氧化物Oxidation 氧化Oxide passivation 氧化层钝化Package 封装 Pad 压焊点Parameter 参数 Parasitic effect 寄生效应Parasitic oscillation 寄生振荡 Passination 钝化Passive component 无源元件 Passive device 无源器件Passive surface 钝化界面 Parasitic transistor 寄生晶体管Peak-point voltage 峰点电压 Peak voltage 峰值电压Permanent-storage circuit 永久存储电路Period 周期Periodic table 周期表 Permeable - base 可渗透基区Phase-lock loop 锁相环Phase drift 相移Phonon spectra 声子谱Photo conduction 光电导 Photo diode 光电二极管Photoelectric cell 光电池Photoelectric effect 光电效应Photoenic devices 光子器件Photolithographic process 光刻工艺(photo) resist (光敏)抗腐蚀剂Pin 管脚Pinch off 夹断Pinning of Fermi level 费米能级的钉扎(效应)Planar process 平面工艺 Planar transistor 平面晶体管Plasma 等离子体 Plezoelectric effect 压电效应Poisson equation 泊松方程Point contact 点接触Polarity 极性 Polycrystal 多晶Polymer semiconductor聚合物半导体 Poly-silicon 多晶硅Potential (电)势Potential barrier 势垒Potential well 势阱Power dissipation 功耗Power transistor 功率晶体管 Preamplifier 前置放大器Primary flat 主平面Principal axes 主轴Print-circuit board(PCB) 印制电路板Probability 几率Probe 探针Process 工艺Propagation delay 传输延时Pseudopotential method 膺势发Punch through 穿通 Pulse triggering/modulating 脉冲触发/调制PulseWiden Modulator(PWM) 脉冲宽度调制Punchthrough 穿通 Push-pull stage 推挽级Quality factor 品质因子 Quantization 量子化Quantum 量子Quantum efficiency量子效应Quantum mechanics 量子力学Quasi – Fermi-level准费米能级Quartz 石英Radiation conductivity 辐射电导率Radiation damage 辐射损伤Radiation flux density 辐射通量密度Radiation hardening 辐射加固Radiation protection 辐射保护Radiative - recombination辐照复合Radioactive 放射性Reach through 穿通Reactive sputtering source 反应溅射源Read diode 里德二极管Recombination 复合Recovery diode 恢复二极管Reciprocal lattice 倒核子Recovery time 恢复时间Rectifier 整流器(管)Rectifying contact 整流接触Reference 基准点基准参考点Refractive index 折射率Register 寄存器Registration 对准Regulate 控制调整Relaxation lifetime 驰豫时间Reliability 可靠性Resonance 谐振Resistance 电阻Resistor 电阻器Resistivity 电阻率Regulator 稳压管(器)Relaxation 驰豫Resonant frequency共射频率Response time 响应时间Reverse 反向的Reverse bias 反向偏置Sampling circuit 取样电路Sapphire 蓝宝石(Al2O3)Satellite valley 卫星谷Saturated current range电流饱和区Saturation region 饱和区Saturation 饱和的Scaled down 按比例缩小Scattering 散射Schockley diode 肖克莱二极管Schottky 肖特基Schottky barrier 肖特基势垒Schottky contact 肖特基接触Schrodingen 薛定厄Scribing grid 划片格Secondary flat 次平面Seed crystal 籽晶Segregation 分凝Selectivity 选择性Self aligned 自对准的Self diffusion 自扩散Semiconductor 半导体Semiconductor-controlled rectifier 可控硅Sendsitivity 灵敏度Serial 串行/串联Series inductance 串联电感Settle time 建立时间Sheet resistance 薄层电阻Shield 屏蔽Short circuit 短路Shot noise 散粒噪声Shunt 分流Sidewall capacitance 边墙电容Signal 信号Silica glass 石英玻璃Silicon 硅Silicon carbide 碳化硅Silicon dioxide (SiO2) 二氧化硅Silicon Nitride(Si3N4) 氮化硅Silicon On Insulator 绝缘硅Siliver whiskers 银须Simple cubic 简立方Single crystal 单晶Sink 沉Skin effect 趋肤效应Snap time 急变时间Sneak path 潜行通路Sulethreshold 亚阈的Solar battery/cell 太阳能电池Solid circuit 固体电路Solid Solubility 固溶度Sonband 子带Source 源极Source follower 源随器Space charge 空间电荷Specific heat(PT) 热Speed-power product 速度功耗乘积Spherical 球面的Spin 自旋Split 分裂Spontaneous emission 自发发射Spreading resistance扩展电阻Sputter 溅射Stacking fault 层错Static characteristic 静态特性Stimulated emission 受激发射Stimulated recombination 受激复合Storage time 存储时间Stress 应力Straggle 偏差Sublimation 升华Substrate 衬底Substitutional 替位式的Superlattice 超晶格Supply 电源Surface 表面Surge capacity 浪涌能力Subscript 下标Switching time 开关时间Switch 开关Tailing 扩展Terminal 终端Tensor 张量Tensorial 张量的Thermal activation 热激发Thermal conductivity 热导率Thermal equilibrium 热平衡Thermal Oxidation 热氧化Thermal resistance 热阻Thermal sink 热沉Thermal velocity 热运动Thermoelectricpovoer 温差电动势率Thick-film technique 厚膜技术Thin-film hybrid IC薄膜混合集成电路Thin-Film Transistor(TFT) 薄膜晶体Threshlod 阈值Thyistor 晶闸管Transconductance 跨导Transfer characteristic 转移特性Transfer electron 转移电子Transfer function 传输函数Transient 瞬态的Transistor aging(stress) 晶体管老化Transit time 渡越时间Transition 跃迁Transition-metal silica 过度金属硅化物Transition probability 跃迁几率Transition region 过渡区Transport 输运Transverse 横向的Trap 陷阱Trapping 俘获Trapped charge 陷阱电荷Triangle generator 三角波发生器Triboelectricity 摩擦电Trigger 触发Trim 调配调整Triple diffusion 三重扩散Truth table 真值表Tolerahce 容差Tunnel(ing) 隧道(穿)Tunnel current 隧道电流Turn over 转折Turn - off time 关断时间Ultraviolet 紫外的Unijunction 单结的Unipolar 单极的Unit cell 原(元)胞Unity-gain frequency 单位增益频率Unilateral-switch单向开关Vacancy 空位Vacuum 真空Valence(value) band 价带Value band edge 价带顶Valence bond 价键Vapour phase 汽相Varactor 变容管Varistor 变阻器Vibration 振动Voltage 电压Wafer 晶片 Wave equation 波动方程Wave guide 波导 Wave number 波数Wave-particle duality 波粒二相性Wear-out 烧毁Wire routing 布线 Work function 功函数Worst-case device 最坏情况器件Yield 成品率Zener breakdown 齐纳击穿Zone melting 区熔法。
到9月9日,社保基金正式进入股市整整3个月,按照有关规定,社保基金必须通过基金管理公司在三个月内完成建仓,并且其持仓市值要达到投资组合总市值80%的水平。
与此前大受追捧的QFII概念相比,社保基金及其所持有的股票显然低调得多,但是在西南证券分析师田磊看来,至少就目前来看,社保基金无论是在资金规模,还是在持股数量上明显都强于境外投资者,其投资理念和行为更可能给市场带来影响。
基金操作的社保基金的选股思路并不侧重某个行业,而更看重企业本身的发展和成长性,并且现阶段的企业经营业绩和走势也不是基金重点考虑的方面。
目前入市的社保基金都是委托南方、博时、华夏、鹏华、长盛、嘉实6家基金管理公司管理。
社保基金大致是被分为14个组合由以上6家管理公司分别管理,每个组合都有一个三位数的代码,第一位代表投资方向,其中“1”指股票投资、“2”指债券投资;第三位数字则代表基金公司名称,其中“1”为南方、“2”为博时、“3”为华夏、“4”为鹏华、“5”为长盛、“6”为嘉实;另有107、108组合主要运作社保基金此前一直持有的中石化股票,分别由博时与华夏基金公司管理。
在许多社保基金介入的股票中经常可以看到开放式基金的身影,例如在被社保基金大量持有的安阳钢铁(600569)的前10大股东中,其第2、6、7、8、9大股东均为开放式基金,而社保基金则以持股500多万股位列第3大股东。
类似的情况也出现在社保基金103组合所持有的华菱管线(000932)上,其第二大股东即为鹏华行业成长证券投资基金,社保基金则以200多万股的持仓量位列第7大股东,此外,在其前10大股东中还有5家是封闭式基金。
对此,某基金公司人士解释说,在获得社保基金管理人资格后,6家基金公司成立了专门的机构理财部门负责社保基金的投资管理,但是其研究、交易系统等则与公募基金共用一个平台,因此社保基金和开放式基金在选股时才会如此一致。
针对“社保概念股”的走势,国盛证券的分析师王剑认为,虽然社保基金此次委托入市资金超过百亿元,但大部分投向是债券,而且由于社保基金的特殊地位,因此基金管理公司对社保基金的操纵策略应该是以“集中持股,稳定股价”为主,不大可能博取太高的收益。
Berry phase in electronic structure theoryIn quantum mechanics,Berry phase is a very important concept that describes the geometric properties of a system in parameter space.In electronic structure theory,Berry phase also plays an important role.It is not only of great significance for understanding the wave function and energy level of electrons,but also plays a crucial role in many physical phenomena.In the theory of electronic structure,Berry phase usually refers to the phase that the electron wave function evolves in the parameter space in a periodic lattice.This phase is dependent on system parameters and can affect the energy of electrons and the shape of wave functions.By calculating the Berry phase,one can gain a deeper understanding of the quantum behavior of electrons and the geometric properties of the system.In many physical phenomena,Berry phase plays an important role.For example,in spintronics, Berry phase can affect the spin state and magnetization direction of electrons.In topological insulators,Berry phase and topological properties are closely related and can affect the band structure and surface state of electrons.In addition,Berry phase can also affect optical and magnetic properties,making it widely applicable in materials science and physics.In recent years,with the continuous development of computer technology,calculating Berry phase has become a hot research field.Many numerical methods and computational software have been developed for calculating Berry phases and related physical quantities.These methods and software can not only be used for theoretical research,but also for the analysis and simulation of experimental data.In summary,Berry phase is a very important concept in electronic structure theory.It is not only of great significance for understanding the wave function and energy level of electrons,but also plays a crucial role in many physical phenomena.With the continuous development of computer technology,calculating Berry phase has become a hot research field,providing important tools and means for theoretical and experimental research.。
a r X i v :p h y s i c s /0503092v 1 [p h y s i c s .a t m -c l u s ] 11 M a r 2005Electronic structure of clusters (LiBC)n :n =1,2and 4G.M.Lombardo,a A.Grassi,a G.Forte,a G.G.N.Angilella,bR.Pucci,b and N.H.March c ,da Dipartimentodi Scienze Chimiche,Facolt`a di Farmacia,Universit`a di Catania,Viale A.Doria,6,I-95126Catania,Italyb Dipartimentodi Fisica e Astronomia,Universit`a di Catania,andIstituto Nazionale per la Fisica della Materia,UdR Catania,Via S.Sofia,64,I-95123Catania,Italyc Departmentof Physics,University of Antwerp,Groenenborgerlaan 171,B-2020Antwerp,Belgiumd OxfordUniversity,Oxford,UKReceived 2February 2008A crystalline form of hole-doped LiBC has been studied,which has been pre-dicted to be superconducting with a transition temperature T c comparable to that of the isoelectronic compound MgB 2[1,2].The structure of LiBC is closely related to the bilayered structure of MgB 2,with Li replacing Mg,and B 2being replaced by BC,but with hexagonal BC layers alternating so that B is nearest neighbour to C both within the in-plane rings,and along the c axis.Although the number of valence electrons decreases by one in replacing Mgwith Li,this is compensated by the substitution of B2by BC.At variance with its similarities with MgB2,a distinctive feature of LiBC is that the Li content in Li x BC can be varied with respect to its stoichiometric value x=1, without any appreciable change of crystalline structure for a quite wide range in x=0.24−1[1],thus allowing to study the superconducting properties of this material upon self-hole-doping.Both MgB2and LiBC are characterized by a similar electronic structure,with a three-dimensional(3D)σsubband,mainly arising from the B2(respectively, BC)layers,and a quasi-bi-dimensional(quasi-2D)πsubband,mainly arising from the electrons delocalization across the layers.The relevance of the prox-imity of theπsubband to a3D–2D crossover,i.e.an electronic topological transition,for the dependence of T c and of the isotope exponent on doping has been emphasized elsewhere within the two-band model of superconductivity [3].Thus,it would be natural to think of both structural and electronic properties of crystalline LiBC as arising from the underlying structural and electronic properties of the individual LiBC units.This has motivated the present study of the electronic structure of the small clusters(LiBC)n,with n going from 1to4.With increasing cluster size n,the solid crystalline and electronic structure of LiBC can be approached,thus allowing one to recognize the origin of the peculiar bilayered structure of the diborides,and the nature of their two coupled electronic bands.The present study shows that such features are already present in clusters(LiBC)n,with n as small as4.For these clusters the electronic stuctures,optimized geometries,and the vi-brational analysis were obtained using the Gaussian03package[4],with ab initio self-consistentfield Hartree-Fock wavefunctions at the6-311+G(d)level of the theory(including polarization and diffuse functions).Each cluster was studied with various spin multiplicities depending on the number of possible uncoupled valence electrons.Here,we report only those which attained a true minimum.At this level of accuracy of the electronic structure studies,we show in Fig.1 the fully optimized geometrical configuration of LiBC for different spin multi-plicities.Table1records the equilibrium bond lengths for Li–Li,Li–C,Li–B, and B–C,for some of the clusters considered in this study.One of the focal points of the present letter is the HOMO-LUMO energy gap ǫHL of the various clusters considered.Therefore in Fig.2for n=1this gap is recorded for the three spin multiplicities studied.There is not a huge spread of ǫHL for n=1with spin multiplicity,but the smallest gap is when this quantity is∼5.The corresponding total Hartree-Fock energies are given in Tab.2for the three different spin multiplicities.Turning to the case n=2,two geometries are shown in Figs.3a and3b,with the relevant equilibrium bond lengths recorded in Tab.1.The‘trans’configu-ration of Fig.3,with multiplicity3,has the lowest energy at the present level of approximation.The corresponding energy gaps for the two configurations are seen not to be very different,with also a relatively weak dependence on spin multiplicity.The largest cluster studied here corresponds to n=4.Fig.4shows the fully optimized configurations of the four isomer quadruplet(LiBC)4clusters.The top row of this Figure has C2v symmetry,whereas the lower Figure symmetry is C1.Studying stability via the normal mode vibrational frequencies,wefind that some frequencies of the extreme right symmetry cluster in the top row of Fig.4are imaginary,all the other isomers presented here being stable in this context.It is appropriate at this point to briefly discuss the geometry of the(LiBC)4 clusters in relation to the crystalline solid form.The main point to emphasize is that in Fig.4the three configurations for which the vibrational frequencies are all real each contain a six-membered ring,consisting of alternating boron and carbon atoms.However,orthogonal to the ring,each configuration has a Li dimer passing through the centre of the ring.Turning to the solid-state structure,Fig.1of Ref.[1]contains two such BC hexagons again,which are intercalated by Li layers.It should be stressed that adjacent hexagons in the solid have no direct B–B or C–C bonds.One discerns a Li–Li axis passing through the centre of the BC hexagons,establishing thereby close contact with the cluster structures already discussed.From Table1,one indeedfinds that the Li–Li distances range between3.30and3.60˚A,to be compared and contrasted with the interlayer Li–Li distance in solid LiBC,which is of3.529˚A [1].Another analogy with the solid phase is provided by the electronic charge distribution in the largest clusters examined in this study.Fig.5therefore shows the Mulliken density charge isosurfaces of the valence electrons,for the (LiBC)4cluster with C1symmetry(Fig.4).One may detect the formation of a ring of electronic charge piling between the C and B atoms,which preludes to theσband in solid LiBC[1].Fig.2shows both a substantial lowering of the energy gapǫHL with increase in cluster size as well as a substantial spread in the values obtained for spin multiplicity9for the four geometries depicted in Fig.4.It is also of interest to note that the dimer(LiBC)2binding energy measured relative to the energy of the two separated LiBC units is found from Table2to be∼4eV.In conclusion,by using quantum chemical techniques,we have studied the Aufbau of crystalline LiBC by gathering individual LiBC units into small(LiBC)n clusters.In particular,we focussed on the structure optimization and the computation of selected electronic properties,such the HOMO-LUMO gap as a function of n and the Mulliken charge density distribution of the largest cluster considered here(n=4),which may provide insight into the salient properties of crystalline LiBC.Already for n=4we can recognize the formation of alternating BC rings,with significant overlap of the valence electrons along the ring,and comparably less electron delocalization in the direction perpendicular to the ring,along which a Li–Li dimer is favoured to align.This is reminiscent of the bilayered structure of crystalline LiBC,and of its two-band electronic character,whose relevance for superconductivity is well-known.References[1]H.Rosner, A.Kitaigorodsky,W. E.Pickett,Prediction of high T csuperconductivity in hole-doped LiBC,Phys.Rev.Lett.88(2002)127001. [2]J.K.Dewhurst,S.Sharma,C.Ambrosch-Draxl,B.Johansson,First-principlescalculation of superconductivity in hole-doped LiBC:T c=65K,Phys.Rev.B 68(2003)020504(R).[3]G.G.N.Angilella,A.Bianconi,R.Pucci,Multiband superconductors close to a2D–3D electronic topological transition,J.Supercond.,accepted for publication ...(2005)...[4]M.J.Frisch,G.W.Trucks,H.B.Schlegel,G.E.Scuseria,M.A.Robb,J.R.Cheeseman,V.G.Zakrzewski,J.A.Montgomery,Jr.,R.E.Stratmann,J.C.Burant,S.Dapprich,lam,A.D.Daniels,K.N.Kudin,M.C.Strain, O.Farkas,J.Tomasi,V.Barone,M.Cossi,R.Cammi,B.Mennucci,C.Pomelli,C.Adamo,S.Clifford,J.Ochterski,G.A.Petersson,P.Y.Ayala,Q.Cui,K.Morokuma,D.K.Malick,A.D.Rabuck,K.Raghavachari,J.B.Foresman, J.Cioslowski,J.V.Ortiz,A.G.Baboul,B.B.Stefanov,G.Liu,A.Liashenko, P.Piskorz,I.Komaromi,R.Gomperts,R.L.Martin,D.J.Fox,T.Keith,M.A.Al-Laham,C.Y.Peng,A.Nanayakkara,C.Gonzalez,M.Challacombe,P.M.W.Gill,B.Johnson,W.Chen,M.W.Wong,J.L.Andres,C.Gonzalez,M.Head-Gordon,E.S.Replogle,J.A.Pople,Gaussian03,Revision B05(2003-12-16), Gaussian,Inc.,Pittsburgh PA(2003).AcknowledgementsGGNA wishes to thank the Department of Physics,University of Antwerp, where this work was brought to completion,for warm hospitality and for the stimulating environment.NHM acknowledges that his contribution to thisstudy was made during a visit to the University of Catania.He wishes to thank the Department of Physics and Astronomy for generous support.Table1Various equilibrium bond lengths(in˚A)for some of the clusters considered in this study.LiBC LiBC LiBC(LiBC)2(LiBC)2(LiBC)2(LiBC)2(LiBC)4(LiBC)4(LiBC)4trans trans C2v(1)C2v(2)C1Li–Li 3.122282 4.245581 3.0483 4.253679 3.353511 3.559604 3.300477 Li–C 1.9624 1.9103 1.9078 2.26 2.1502 2.298 2.4106 2.343600 2.646053 2.2972742.2568 2.1433 2.2981 2.1345 2.215844 2.22583 2.2660672.4572 2.4293 2.6453 2.0751 2.215844 2.22583 2.2185182.1353 4.6509 2.1503 4.1552 2.3436 2.646053 2.2927532.215844 2.22583 2.2653262.215844 2.22583 2.2231542.522509 2.02507 2.3166412.522509 2.02507 1.9402652.476577 2.2179492.476577Li–B 1.9624 3.289 2.2398 2.4814 2.574 3.0006 3.3345 2.146662 2.261255 2.2133582.4838 2.18493.0007 2.1358 2.146662 2.29926 2.2742972.2551 2.1058 2.1078 2.1539 2.268792 2.261255 2.2601062.25433.2111 2.1078 2.8393 2.289784 2.261255 2.2109452.268792 2.29926 2.2747072.268792 2.261255 2.2606122.289784 2.45892 2.2113032.268792 2.45892 2.1571412.329519 2.3314812.329519B–C 1.3944 1.3787 1.6026 1.4185 1.4066 1.3508 1.4131 1.530041 1.489521 1.4965763.28224.0533 3.8477 4.1366 1.546234 1.485995 1.5673491.3999 1.4091 1.4583 1.3942 1.499536 1.473746 1.4845841.4186 1.4496 1.3868 1.4616 1.534722 1.515207 1.5292491.534722 1.515207 1.5166921.571215 1.63323 1.6533841.546234 1.485995 1.6207021.499536 1.473746 1.49723S=1S=3S=5Fig.1.Fully optimized configuration of the LiBC singlet cluster for S=1,3,5(left to right;Li:purple;B:pink;C:grey).Table2Calculated properties of(LiBC)n clusters.All energies are in hartrees.n S E HF E HF/nα-HOMOα-LUMOβ-HOMOβ-LUMOS =1S =1(trans)S =3S =3(trans)Fig.3.(a),top row:Fully optimized configurations of the two isomer singlet (LiBC)2clusters.(b),bottom row:Fully optimized configurations of the two isomer triplet (LiBC)2clusters.S =9,C 2v (1)S =9,C 2v (2)S =9,C 2v (3)S =9,C 1Fig.4.Fully optimized configurations of the four isomer quadruplet (LiBC)4clusters with C 2v symmetry (top row)and C 1symmetry (bottom).Some of the frequencies of the C 2v (3)are imaginary,the other three isomers shown being stable.Fig.5.Isosurfaces of the valence electron density for the(LiBC)4cluster with C1 symmetry in Fig.4.Each isosurface is labeled with the relative value of the electrondensity(0.10−0.20),while each atom is labeled with its Mulliken atomic charge.。