离散变分方法研究PuH3分子的电子结构

目前还没有公开的关于PuH3的分子结构和分子光谱的资料与数据.基于密度泛函理论的全数值自洽场计算方法--离散变分方法数值解相对论Dirac方程,在自由的钚原子和氢原子波函数的数值基及原子能级基础上计算了PuH3分子的不同几何结构及势能曲线.等边三角棱锥形PuH3分子基态的数据为Pu-H的键长l=2.098×10-10m,键角θ(∠H-Pu-H)=119.102°,H-H的距离为3.617×10-10m,轨道总能量为-86 628.701×10-18J,费米能级Ef=-16.856 eV.分析了反演对称等价的分子态以及非质心坐标对轨道总能量的影响.     

对称外场作用下椅型环戊酮分子的结构和性质

采用密度泛函理论(DFT)中的B3P86/6-311++G(d,p)方法,计算得到环戊酮(椅型)分子沿x轴方向在不同对称电场(-0.006~0.006)作用时的基态几何结构、电偶极矩和分子总能量.计算结果表明:电场强度大小影响分子的几何构型;分子偶极矩随电场强度的增加而增大;当电场强度F=0时,分子总能量为-271.481 6,分子总能量随电场强度的增加而降低;当F=-0.006时达到最大值-271.475 2,系统总能量随电场强度的增加而逐渐降低.     

非对称外电场作用下C_8H_(14)O分子的结构和性质

基于密度泛函理论(DFT)中的B3P86方法,在6-311++G(2df)基组水平上,计算得到C8H14O分子沿x轴方向加非对称电场(-0.008 0~0.002 5)时的基态几何构型、电偶极矩和分子总能量.计算结果表明:电场强度大小影响分子的几何构型;随着电场强度的增加,分子偶极矩先减小再增大;当电场强度F=0时,分子总能量为-389.881 8,随着电场强度的增加,分子总能量升高,当F=0.002 5时达到最大值-389.879 9;随着电场强度的增加,系统总能量逐渐升高.     

把VRDDO法直接用于高斯基函数简化量子化学从头计算法

我们发现,高斯基函数m,n间的交盖因子?? 可用来作为判据去判断这对高斯基函数是否可看作为是“小”的,使得包函它们的各种积分都可忽略不计,同时保持预期的精确度,其中α_m,α_n表示其轨道指数,r_m,r_n表示其中心的位置向量.在苯分子的STO-3G计算中,如以10~(-4)作为阈值,则各被占轨道能量和分子总能量、各原子轨道和各原子的总集居数的计算精确度一般都可达10~(-4)(原子单位),最大误差为10~(-3)左右.所必需计算的二电子四中心积分数可减少为1/1.8左右.如分子愈大、表达每一原子轨道所用的高斯基函数愈多,则此法在节约计算量方面的效果可更显著.在计算过程中并毋需为此作额外的计算.也不需要增加额外的存储量.     

平面B_nBe_3(n=1~6)团簇的结构和稳定性的理论研究

利用CCSD(T)/6-311+G(d)//B3LYP/6-311+G(d)方法对平面BnBe3(n=1~6)的结构、稳定性及势能面进行了研究.通过计算获得了BnBe3(n=1~6)团簇的最稳定结构.平均原子成键能(BE)、成键能增量(IBE)和能量二次差分(Δ2E)的变化图揭示了B4Be3具有较高的稳定性.结果表明,BnBe3(n=1~6)团簇的稳定性与离域π分子轨道、σ正切分子轨道和σ径向分子轨道的相互作用有关.价轨道、ADNDP、ELF和NICS分析证明了B2Be3的第3个异构体具有σ-和π-双芳香性.     

TFDW理论在双原子分子计算中的应用

应用Thomas-Fermi-Dirac-Weizsācker(TFDW)变分方程,计算了双原子分子 XH(X=Li,Be,B)的基态总能量及轨道能级。基态总能量与Hartree-Fock结果符合得较好。     

丙二烯分子结构的量子化学从头计算

采用 PSHONDO- SCF全电子从头计算程序 ,对丙二烯分子的两种不同对称性构型的电子结构进行计算 .结果表明丙二烯分子 ,采用 D2 d对称结构比 D2 h结称结构更稳定 .丙二烯分子(D2 d)的电子结构 :(1)总能量为 - 5.0 4 2 94 6 2 0× 10 -16J,前线轨道 HOMO为 E(2 e) =- 1.6 4 0192 56× 10 -18J,LU MO为 E(3e) =7.6 6 110 52 4× 10 -19J;(2 )键级直接相键连的 C- H为 0 .3814,C=C为 0 .6 7711;(3)电荷分布—— C(1) 为 - 0 .1758,C(2 ) 和 C(3 ) 均为 - 0 .2 2 4 8,H为 0 .156 4     

铝在冰晶石-氧化铝熔液中溶解机理的量子化学研究

利用EHMO(扩充许克尔分子轨道)函数计算离子数达50个的原子(离子)模型,采用Hoffmann的ICON程序以非迭代方式计算。设计了一系列简单原子簇模型以计算其分子轨道波函数和其他数据,从而考查铝原子和Al~+在不同离子环境中的微观行为。认为Al在Na_3AlF_6-Al_2O_3熔液中溶解反应主要是铝与Al~(3+)和Na~+离子以某种程度的共价键结合,形成[Al_nNa_m]~(x+)一类的原子簇离子。m,n及x的数值有待进一步确定。     

类锂体系1s22p2P态能量的相对论修正

利用不可约张量理论,导出了锂原子(含类锂离子)能量的相对论修正(包括相对论质量修正、达尔文修正、自旋-自旋接触相互作用和轨道-轨道相互作用)的解析表达式,在此基础上具体计算了类锂体系(Z=3→7)激发态1s22p 2P的总能量,所得计算结果与实验数据符合得较好.     

三元团簇X_3(X=S,Se,Te)的结构与芳香性(英文)

使用B3LYP,MP2和CCSD(T)3种方法研究了三元团簇X3(X=S,Se,Te)的几何结构,振动频率,原子化能和总能量.计算的核独立化学位移(NICS)指出在三元结构上存在强的电子环流.详细的分子轨道分析指出有一个高度离域化的σ和一个π分子轨道,它们在多重芳香性中有重要的作用.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that