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Using the DFT/B3LYP method with the basis set 6-31G*(**), we analyzed the vibrational spectra of the conformers phenyldichlorarsine
and phenyldichlorphosphine in the anharmonic approximation.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 557–559, July–August, 2005. 相似文献
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Letters in Mathematical Physics - 相似文献
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应用包含非迭代三激发(CCSD(T))、迭代三激发(CC3)及其变体(CCSDT-3)的耦合簇理论(CC)和密度泛函理论(DFT)之B3LYP方法,使用直到五阶的自洽相关一致基组aug-cc-pVxZ/aug-cc-pVxZ-PP(x=T, Q, 5),首先优化出HOI的平衡结构,接着在该结构附近采样势能点并将其在简正坐标下拟合成直到四阶的多项式力场,依据该力场结合振动自洽场(VSCF)、振动组态相互作用(VCI)和二阶振动微扰理论(VPT2)进行非谐振动分析,精确预期了HOI的基频、直到v1+v2+v3=3的和频与倍频,得到其转动常数、旋振相互作用常数、非谐性常数和离心畸变常数,同时振子强度被估计,氘取代效应被进一步考察。结果表明:当前计算值与已知实验结果符合良好,其中耦合簇理论计算的振动光谱常数更加可靠,DFT误差明显偏大,但两者计算的振动频率却相当一致;并非基组越大,计算得到的非谐振动常数/频率与实验更符合,总体来讲CC3和CCSDT-3的结果更值得信赖;HOI/DOI都没有共振发生。 相似文献
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在密度泛函理论水平上研究了从DNA碱基单体到Watson-Crick碱基对的结构、电荷分布、以及非谐性振动参数的变化. 通过研究参与碱基对中多重氢键的NH2、N-H和C=O的伸缩振动模式,预测了这些模式的对角非谐性常数、非对角非谐性常数、以及非谐性振动耦合对碱基结构变化的敏感性. 研究结果揭示了DNA碱基中非谐性振动势、分子间氢键和静电相互作用之间的内在联系. 相似文献
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近年来,许多国家开展了用非晶硅(a-Si:H)作为探测器材料的研究,并取得了明显的进展.本文简要介绍这种探测器的原理、结构、现状及其应用前景. Recently, the investigation to make radiation detectors with amorphous Silicon(a-Si:H) were reported in many countries of the world. In this paper, operation principles,structures, current status and prospect of applications in various fields of science on these detectors were reviewed briefly. 相似文献
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Higher Order Squeezed States of Anharmonic Oscillators 总被引:1,自引:0,他引:1
Ji-Suo Wang Tang-Kun Liu Ming-Sheng Zhan 《International Journal of Theoretical Physics》2000,39(11):2583-2593
In this paper the N eigenstates of the Nth powers (N 3) of the annihilationoperator of an anharmonic oscillator are constructed and their completeness isinvestigated. We introduce a new kind of higher order squeezing, Mth-order SU(1,1) squeezing. The properties of Mth-order SU(1, 1) squeezing and anticorrelationof the N states are studied. The result show that these states may form a completeHilbert space; the Mth-order [M = (n + 1/2)N;n = 0,1, ...] SU(1, 1) squeezingeffects exist in all of the N states when N is even. There is anticorrelation in allof them. 相似文献
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采用基于第一性原理的赝势平面波方法,对3个不同密度(2.6,2.9和3.2 g·cm-3)非晶碳结构的振动态密度和振动拉曼光谱进行了研究。结构模型由快速“液体-淬火”方法模拟得到,振动频率和本征模由线性响应理论决定,拉曼耦合张量由有限电场方法计算。计算结果表明:当密度从2.6增加到3.2 g·cm-3时,sp3碳含量从50%增加到84.4%,G峰向高频区偏移,D峰和G峰的强度之比ID/IG减小,T峰向低频区偏移且T峰和G峰的强度之比IT/IG增大。该结果与实验结果显示出很好的一致性。依据原子振动的分析结果证实:拉曼光谱的G峰和D峰均来自于sp2碳原子的振动贡献,且G峰是由任何成对的sp2碳原子的伸缩振动产生的,T峰来自于sp3杂化碳原子的振动贡献,G峰和T峰峰位随结构的色散是由键长变化导致的。 相似文献
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Isao Suzuki 《应用光谱学评论》2013,48(1):249-301
It is well known that the anharmonic part of the molecular potential function contributes to the vibration-rotation energy and to the apparent molecular geometry, although the anharmonic effect is not so profound as that from its harmonic counterpart. Nevertheless, it cannot simply be ignored for the precise treatment of molecular dynamics and structures. For a better understanding of the molecular potential function, it is highly desirable to extend the force constant calculation to evaluate the terms beyond quadratic, which will give a more realistic potential map of polyatomic molecules for wider ranges of atomic displacements. The vibrational anharmonicity also affects the transition intensities through the mixing vibration-rotation wave functions. 相似文献
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采用量子限制效应模型对镶嵌有纳米非晶硅粒子的氢化氮化硅薄膜的光吸收进行了理论模拟,探讨了由吸收谱分析给出该结构薄膜光学参数的方法,并通过对不同氮含量样品的讨论给出了量子限制效应和纳米硅粒子表面的结构无序对薄膜光吸收特性的影响规律。分析结果表明,随氮含量的增加,薄膜有效光学带隙增大,该结果与薄膜中纳米硅粒子平均尺寸的减小引起的量子限制效应的增强相关,而小粒度纳米硅粒子比例增加所引入的较高微观结构无序度和较多缺陷将会导致薄膜低能吸收区吸收系数增加。 相似文献
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采用等离子体增强化学气相沉积法生长的单层本征氢化非晶硅薄膜对单晶硅片进行钝化,结果表明增加氢稀释比有利于减少薄膜中的缺陷,增强钝化效果,过量的氢稀释比会导致非晶硅在硅片表面的外延晶化生长,降低钝化效果。退火导致非晶硅晶化程度增加,降低了钝化效果,同时退火提升了薄膜的质量,改变了H键合方式,增强了钝化效果。因此,单层氢化非晶硅只有在合适的氢稀释比和退火温度才可以获得最佳钝化效果。为了提高非晶硅薄膜对硅片的钝化效果,采用具有高低氢稀释比的叠层本征非晶硅薄膜对硅片进行钝化。因此将高氢稀释比沉积的非晶硅薄膜叠层生长于低氢稀释比的薄膜之上,避免非晶硅在硅片表面的外延生长。在退火过程中,高氢稀释比薄膜中的氢扩散到低氢稀释比薄膜中,有效地钝化了非晶硅中和单晶硅表面的悬挂键,改善了非晶硅/硅片的界面质量,叠层钝化后硅片的少子寿命为7.36 ms,隐含开路电压为732 mV。 相似文献
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The rotational spectra of the unstable HCCCP molecule have been investigated in the millimeter-wave region for the main excited vibrational states which lie below 1000 cm(-1), namely nu(4) (C&bond;C stretch), nu(5) (HCC bend), nu(6) (CCC bend), nu(7) (CCP bend), 2nu(6), 2nu(7), 3nu(7), 4nu(7), nu(5) + nu(7), and nu(6) + nu(7). l-type resonance effects have been taken into account in the analysis of the spectra, so that the values of the anharmonicity constants x(L(66)), x(L(77)), x(L(57)), and x(L(67)) could be determined. The anharmonic interactions which couple the nu(4) state with nu(6) + nu(7), 2nu(6), and 4nu(7) have been also considered, yielding the unperturbed value of the alpha(4) vibration-rotation coupling constant. Copyright 2001 Academic Press. 相似文献
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