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1.
在B3LYP/6-311++G(d,p)、B3LYP/6-311++G(3df,2p)和B3P86/6-311++G(3df,2p)水平优化计算了锗亚按、磷杂烯、磷杂锗烯和砷杂硅烯以及标题物质子化正离子的平衡几何构型.用优化计算的平衡几何构型,在B3LYP/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p)计算了各标题物的旋转势垒.在B3LYP/6-311++G(d,p)//B3LYP/6-311++G(d,p),B3LYP/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p)和B3P86/6-311++G(3df,2p)//B3P86/6-311++G(3df,2p)计算了各标题物的质子亲和能,质子化反应自由能(ΔG 298)和质子化反应的焓变(ΔH 298).计算结果表明标题物有较强的π键和负值较大的质子亲和能、ΔG 298和ΔH 298,有稳定的质子质子化正离子产物.计算的旋转势垒标表标题物分子有比较强的π键,质子化正离子的π键比对应的中性分子强.  相似文献   

2.
使用abinitio(HF)和密度泛函法(B3LYP,B3P86),在6-311 G(d,p)和6-311 G(3df,2p)基组水平下,对硅杂硫烯酮及其相关分子进行了优化构型的量子化学计算.计算结果表明,标题物Ⅰ和Ⅲ为反式弯曲几何构型,Ⅱ为弯曲几何构型,Ⅳ为线性平面分子.NBO分析表明,Ⅰ中Si原子上有孤对电子,Ⅱ和Ⅲ中有弯曲Si-Cπ键.  相似文献   

3.
使用ab initio(HF)和密度泛函法(B3LYP,B3P86),在6-311 G(d,p)和6-311 G(3df,2p)基组水平下,对锗杂硫烯酮及其相关分子进行了优化构型的量子化学计算.计算结果表明,标题物Ⅰ和Ⅲ为反式弯曲几何构型,Ⅱ和Ⅳ为弯曲几何构型.NB0分析表明,Ⅰ中Ge原子上有孤对电子,Ⅱ、Ⅲ、Ⅳ中有弯曲弱σ键,该键有明显的π键性质,Ⅰ中有C(←=)O键,Ⅲ中有C(←=)S键.  相似文献   

4.
使用ab initio(HF)和密度泛函法(B3LYP,B3P86),在6-311 G(d,p)和6-311 G(3df,2p)基组水平下,对硅杂锗杂硫烯酮及其相关分子进行了优化构型的量子化学计算.计算结果表明,全部标题物Ⅰ到Ⅵ为反式弯曲几何构型.NBO分析表明,在各标题物中,末端Si、Ge原子上有孤对电子,标题物Ⅰ和Ⅳ中有Si←=O键,标题物Ⅱ中居中的Si原子上有p成份为主的空轨道,标题物Ⅲ中有Ge←=O键,标题物Ⅴ中有Ge←=S键,标题物Ⅵ中有Si←=S键.  相似文献   

5.
用量子化学从头计算(HF)和密度泛函理论(DFT)对1,3-磷锗丙二烯及其相关分子进行了研究.在6-311 G(d,p)和6-311 G(3df,2p)基组水平优化上计算了各标题物的平衡几何构型.结果表明:1,3-磷锗丙二烯及1,2,3-磷硅锗丙二烯为弯曲几何构型,负离子也为弯曲几何构型.另外,在B3LYP/6-311 G(d,p)水平上计算了各标题物的旋转势垒,定性估算了各标题物分子中Ge=C、Ge=Si、C=P、Si=P和Ge=P等双键的相对强度.  相似文献   

6.
对CH(X^П)自由基与NH3的反应进行了量子化学研究.分别在B3LYP/6—311 G(d.p),B3LYP/6—311 G(3df,3pd).MP2/6—311 G(d.p)和MP2/6—311 G(3df,3pd)水平优化了反应势能面上各驻点的几何结构.并在QCISD(T)/6—311 G(3df,3pd)水平上计算了各驻点的能量.通过IRC计算确认了过渡态.确定了反应的机理.  相似文献   

7.
在UB3L YP/6-311 G(d,P)、UB3L YP/6-311 G(3df,2p)、UB3L YP/AUG-CC-PVTZ,UQCISD/6-311 G(d,p)水平优化得到了N2S2单、三重态的平衡几何构型,发现单重态N2S2为能量最低的稳定分子。用优化的最稳定单重态N2S2结构在UB3L YP/6-311 G(d,p)//UB3L YP/6-311 G(d,P),UB3L YP/6-311 G(3df,2p)//UB3L YP/6-311 G(3df,2p)计算同键反应芳香性稳定化能(HASE)。用基团加和法(group increment approach)在UB3L YP/6-311 G(d,P)//UB3L YP/6-311 G(d,P)和UB3L YP/6-311 G(3df,2p)//UB3L YP/6-311 G(3df,2p)水平计算磁化率增量(A),计算结果表明N2S2分子的键长发生了平均化。同键反应芳香性稳定化能和磁化率增量均为负值.表明N2S2具有芳香性.实现了N2S2分子芳香性的几何、能量和磁性的判定.  相似文献   

8.
在RHF/6-31G(d,p),RHF/6-6-31+G(d,p),MP2/6-31+G(d,p)和B3LYP/6-31+G(d,p)水平优化得到了桶烯和相关分子的平衡几何构型,进一步用MP2/6-31G(d,p)//RHF/6-31+G(d,p),MP2/6-31+G(d,p)//RHF/6-31G+(d,p)和B3LYP/6-31+G(d,p)//BLYP/6-31+G(d,p)水平计算桶稀、双环[2.2.2]-辛二稀和双环[2.2.2]-然的气相氢化热(△H^0(298K),气相氢化自由能(△G^0(298K)和同键反应芳香性稳定化能(HASE),计算结果指出桶烯有的G(sp^2)-C(sp^3)单链,小的∠C-C-=C键有和比较大的氢化热,同键反应芳香性稳定化能为正值,表明桶烯为反双环芳香性分子,实现了标合物反芳香性的几何、能量的判定。  相似文献   

9.
对CH(X2Ⅱ)自由基与NH3的反应进行了量子化学研究.分别在B3LYP/6-311++G(d,p),B3LYP/6-311++G(3df,3pd),MP2/6-311++G(d,p)和MP2/6-311++G(3df,3pd)水平优化了反应势能面上各驻点的几何结构,并在QCISD(T)/6-311++G(3df,3pd)水平上计算了各驻点的能量.通过IRC计算确认了过渡态,确定了反应的机理.  相似文献   

10.
O(1D)与CF3Cl反应的理论研究   总被引:3,自引:0,他引:3  
用量子化学密度泛函理论(DFT)方法,对O(^1D)与CF3CI的反应进行了研究.在B3LYP/6-311+G(d),B3LYP/6-311+G(2df,2pd)计算水平上,优化了反应物、产物、中间体和过渡态的几何构型。并在QCISD(T)/6-311++G(d,p)水平上计算了单点能量,为了确证过渡态的真实性,在B3LYP/6-311+G(d)水平上进行了振动分析.研究结果表明,O(^1D)与CF3Cl反应中存在4个反应通道,其中生成产物:P1(CF3O+Cl)和P2(CF3+CIO)的通道应为主反应通道.  相似文献   

11.
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.  相似文献   

12.
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。  相似文献   

13.
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.  相似文献   

14.
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-  相似文献   

15.
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-  相似文献   

16.
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  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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