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61.
S. Caravati G.P. Brivio S. Pagliara G. Galimberti C. Giannetti 《Surface science》2006,600(18):3901-3905
Recent advances in both the experimental resolution and in the computational capabilities motivate new studies of surface properties. In particular, a detailed comparison between theoretical and experimental data is expected to provide a better insight into surface and image states. In this work we present a joint effort analyzing such features of the Cu(1 1 1) and Cu(0 0 1) surfaces. The experiments are performed by using both linear and non-linear angle-resolved photoemission. From the theoretical point of view, we make use of the Green function embedding technique within density functional theory. We are able to account for the image states by suitably modifying the effective potential in the Kohn-Sham equation and the generalized boundary conditions on the Green function. Comprehensive theoretical and experimental results on the effective mass and the binding energy of the Shockley state and the first image states are reported. 相似文献
62.
D. Ray P.K. Mukherjee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(1):89-92
Stability and energy of the excited states of the ion in plasmas are investigated theoretically using the Debye model. The transition energies of and transitions are seen to follow completely opposite trends of variation with the plasma screening strength. The dependence
of absorption oscillator strength values on the screening strength is also discussed.
Received: 22 October 1997 / Accepted: 9 January 1998 相似文献
63.
强场对Au4团簇性质的影响 总被引:1,自引:1,他引:0
采用与时间相关的局域密度泛函 (TDLDA/B3LYP)方法研究Au4团簇的几何构型、分子轨道能级分布和激发能在强激光场中的变化.计算结果表明:电场不能改变Au4团簇的几何构型,随着电场的增加,电离势和电子亲和势增加,而费米能级和能隙减小.通过比较不同电场强度下激发能,指出要产生超短波脉冲或实现X射线软化,强激光场中的团簇的高次谐波是一种可能的途径. 相似文献
64.
锁模Yb:S—FAP激光器 总被引:1,自引:0,他引:1
本文首次报道了连续波Ti:Sapphire纵向泵浦主动锁模Yb:S-FAP激光器。实验得的最短锁模脉宽为35.4ps,通过特殊设计的定态激发光谱实验,我们对它的锁模特性进行了研究,因为从理论上说Yb:YS-FAP4nm的荧光线宽应能得到更短的变换极限脉宽。 相似文献
65.
团簇LaO的理论研究 总被引:3,自引:3,他引:0
采用密度泛函理论研究LaO团簇体系。中性分子LaO的基态是两重态(2Σ),阴离子LaO-和阳离子LaO 的基态都是单重态(1Σ)。使用不同的方法计算团簇LaO的电子亲和能和电离能。计算结果表明用BLYP方法和弥散极化基组计算结果和实验数据吻合较好。用含时密度泛函理论计算团簇LaO的低能激发态,从理论上归属LaO-的光电子能谱的谱峰和LaO的吸收光谱的谱峰。计算得到与实验一致的结果。 相似文献
66.
Zbigniew Kisiel Lech Pszczó?kowski Manfred Winnewisser Eric Herbst 《Journal of Molecular Spectroscopy》2005,233(2):231-243
We report the results of a comprehensive reinvestigation of the rotational spectrum of diethyl ether based on broadband millimetre-wave spectra recently recorded at The Ohio State University and in Warsaw, covering the frequency region 108-366 GHz. The data set for the ground vibrational state of trans-trans diethyl ether has been extended to over 2000 lines and improved spectroscopic constants have been determined. Rotational spectra in the first excited vibrational states of the three lowest vibrational modes of trans-trans-diethyl ether, ν20, ν39, and ν12 have been assigned. The v20 = 1 and v39 = 1 states are near 100 cm−1 in vibrational term value and are coupled by a strong c-axis Coriolis interaction, which gives rise to many spectacular manifestations in the rotational spectrum. All of these effects have been successfully fitted for a dataset comprising over 3000 transitions, leading to precise determination of the energy difference between these states, (ΔE/hc)=10.400222(5) cm−1. A newly developed software package for assignment and analysis of broadband spectra is described and made available. 相似文献
67.
G.D. Roston Z.F. Ghatass 《Journal of Quantitative Spectroscopy & Radiative Transfer》2006,101(2):205-209
A set of intercombination rules has been used to calculate the two excited (30 and 31) state potential parameters ε12 and R12 of Hg, Cd and Zn interacting with inert gases (Xe, Kr, Ar and Ne). The results obtained with these rules are compared with various experimental and theoretical results for these molecules. The rules can be very well used for determination of the position of the potential minimum for the two states of all molecules. Concerning the well depths of the two states (30 and 31) of these molecules, it is observed that for the more bounded excited state 30 some of these rules give results that are in close agreement with experimental data especially for molecules consisting of heavy atoms but for the shallow excited state 31 these rules cannot be used. 相似文献
68.
Heinz Falk Peter Wolschann Ulrich Zrunek 《Monatshefte für Chemie / Chemical Monthly》1984,115(2):243-249
ThepK
a
-value corresponding to the deprotonation of (4Z, 9Z, 15E)-2,3-dihydrobilatriene-abc was measured to be 13.6±0.1 using a stopped flow equipment. This represents a 50-fold decrease in acidity compared to the corresponding all-(Z) diastereomer. Also the pyrromethene type basicity of the (Z,Z,E) diastereomer is decreased by a factor of ten. By applying aFörster cycle a fundamental difference between the two diastereomers is revealed: Only the all-(Z) diastereomer exhibits a cross over of relative acidity and basicity on moving from ground to excited state. 相似文献
69.
采用多组态相互作用方法及Rayleigh- Ritz变分法,计算了类铍O4+离子1s22s2p3Po态的非相对论能量,并详细分析了如何选择质量最好的变分波函数.运用截断变分方法进一步饱和函数空间得到能量的改进量,并考虑相对论修正、质量极化效应等获得了相对论能量计算值.计算结果表明,此理论计算方法可得到高精度的能量计算值. 相似文献