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采用二项式方案构建了FenOm+(n+m=4)团簇的大量可能初始结构.运用广义梯度近似(GGA)密度泛函理论中的PW91交换关联泛函对这些初始结构进行优化和频率分析,得到12个稳定的异构体.在此基础上计算和分析了它们的结合能、对称性、键长、磁矩,最高占据轨道与最低未占据轨道的能隙.发现Fe—O键在FenOm+(n+m=4)团簇的稳定中具有重要作用,团簇的总磁矩主要取决于铁原子的磁矩和各个原子磁矩排布情况. 相似文献
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马晓光 《原子与分子物理学报》2009,26(1):34-38
利用多体微扰理论,把基态锂原子K和L壳层电子的光电离过程中的电子相关效应计算到了无穷阶。用Feynman图技术讨论了基态关联效应和混相近似效应,并计算了与无穷阶末态关联的耦合效应。计算结果与实验和其他理论结果吻合得很好。 相似文献
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利用单个原子精确的光电离散射截面和物质的复介电常数,并考虑一定的分子力学模型,可以对凝聚态物质中的原子光电离截面进行定量研究。孙卫国等最近提出了一套研究真实体系中原子光电离截面的新方法。本首次应用它们来研究碱土金属钠在不同密度状态下的光电离截面,结果表明新的光电离截面公式比名的孤立原子光电离截面公式更具有优越性。 相似文献
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利用我们提出的普遍适用的精确光电离截面公式和介电影响函数研究了原子光电离共振结构受粒子数密度影响的效应.结果表明用新的光电离截面公式可以直接处理宏观环境对截面的影响,明显地优于孤立原子光电离截面公式. 相似文献
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An alternative expression for photoionization cross-section of atoms or molecules and a dielectric influence function (DIF) in a high-density system proposed recently are used to study the photoionization cross-sections of solid silver. It is suggested that a density turning point (DTP) of a photoionized system may be viewed as the critical point where the photoionization properties of atoms in a real system may have a notable change. The results show that the present theoretical photoionization cross-sections are in good agreement with the experimental results of a silver crystal both in structure and in magnitude. 相似文献
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基于翟红生和韩克利给出的势能面[Zhai H S, Han K L 2011 J. Chem. Phys. 135 104314], 运用准经典轨线方法对H+NH及其同位素取代反应的立体动力学性质进行了理论研究. 分别计算并讨论了碰撞能Ec=8和16 kcal/mol时反应的极化微分反应截面、两矢量k-j'相关分布函数P(θr)、 三矢量 k- k'- j'相关分布函数P(φr)、空间分布函数P(θr, φr). 结果表明, 对于上述的两个碰撞能, 由于同位素取代反应中质量因子的不同, 同位素效应对H+NH反应的立体动力学性质的影响很明显. 相似文献
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Photoabsorption cross sections of the alkaline-earth-metal elements under strong interaction conditions
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The strong interatomic interaction effects on photoabsorption cross sections of a private atom have been interpreted by the contribution of both the real and imaginary parts of atomic polarizability in the present work. Some unresolved differences between the photoabsorption cross sections of isolated atoms and those of condensed atoms, especially near thresholds and resonances, probably could be interpreted by the competition between the imaginary and real parts of atomic frequency-dependent polarizabilities. 相似文献
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Theoretical study of the influence of intense femtosecond laser field on the evolution of the wave packet and the population of NaRb molecule
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Employing the two-state model and the time-dependent wave
packet method, we have investigated the influences of the parameters of the intense
femtosecond laser field on the evolution of the wave packet, as well
as the population of ground and double-minimum electronic states of
the NaRb molecule. For the different laser wavelengths, the evolution of
the wave packet of 6{ }^1\Sigma ^ + state with time and
internuclear distance is different, and the different laser
intensity brings different influences on the population of the
electronic states of the NaRb molecule. One can control the evolutions
of wave packet and the population in each state by varying the laser
parameters appropriately, which will be a benefit for the light
manipulation of atomic and molecular processes. 相似文献