共查询到19条相似文献,搜索用时 62 毫秒
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利用多重散射团簇方法 (MSC)对吸附系统SO2 /Ag(110 )的S原子K边X射线吸收精细结构谱 (NEXAFS)作了理论分析 .研究表明 ,覆盖度为 0 5时 ,吸附的SO2 的S—O键长比气体状态时增长了 (0 0 14± 0 0 0 6 )nm ,OSO键角减小了 15°± 5°;SO2 分子的S原子处于芯位 ,但两个O原子处于不对称的位置 ;分子平面与 (110 )的夹角约为5 2° ,同时分子平面相对衬底表面法线有一小角度的倾斜 .MSC计算证实了该吸附系统存在一介于π 与σ 态中间的共振结构 ,这是由SO2 与衬底相互作用而诱导的 相似文献
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利用多重散射团簇方法(MSC)对吸附系统SO2/Ag(110)的S原子K边X射线吸收精细结构谱(NEXAFS)作了理论分析.研究表明,覆盖度为0.5时,吸附的SO2的S—O键长比气体状态时增长了(0.014±0.006)nm,OSO键角减小了15°±5°;SO2分子的S原子处于芯位,但两个O原子处于不对称的位置;分子平面与(110)的夹角约为52°,同时分子平面相对衬底表面法线有一小角度的倾斜.MSC计算证实了该吸附系统存在一介于π关键词:
X射线吸收精细结构
2/Ag(110)')" href="#">吸附系统SO2/Ag(110)
多重散射团簇方法 相似文献
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用多重散射团族方法对SO2/Ni(111)吸附系统的S原子ls近边X射线吸收精细结构进行了详细的计算和分析,求得吸附系统的局域结构。研究结果证实了SO2分子在Ni(111)表面是平铺吸附的,其最佳吸附位为fcc三度芯位。吸附分子的S—O键长比气体状态时增长了(0.007±0.002)nm,分子键角∠OSO减小了10°,SO2距衬底的吸附高度为(0.20±0.02)nm。理论计算与两组实验结果进行了直接比较。
关键词:
局域吸附结构
X射线吸收精细结构
2/Ni(111)')" href="#">吸附系统SO2/Ni(111)
多重散射团簇方法 相似文献
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运用密度泛函理论, 研究了CO2在Yn (n=2-8) 团簇表面的吸附结构和电子性质。结果表明:CO2吸附于 Yn (n=2-8)团簇表面时,线型的分子结构畸变为三角形构型。YnCO2表现出了较大的吸附能 (大于3eV)。吸附使体系的能隙表现出了奇偶振荡效应。吸附后,C-O键伸长,C原子由电子施体变为受体,O原子所带电子数也显著增加。在所有尺寸中,Y4CO2 、Y6CO2稳定性最好。 相似文献
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运用密度泛函理论, 研究了CO2在Yn (n=2-8) 团簇表面的吸附结构和电子性质。结果表明:CO2吸附于 Yn (n=2-8)团簇表面时,线型的分子结构畸变为三角形构型。YnCO2表现出了较大的吸附能 (大于3eV)。吸附使体系的能隙表现出了奇偶振荡效应。吸附后,C-O键伸长,C原子由电子施体变为受体,O原子所带电子数也显著增加。在所有尺寸中,Y4CO2 、Y6CO2稳定性最好。 相似文献
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本文采用密度泛函理论的广义梯度近似,研究了Sc原子修饰的Si@Al_(12)团簇与CO分子之间的相互作用.结果显示:Sc原子倾向于以穴位的形式吸附于Si@Al_(12)团簇表面;Sc周围最多可以吸附7个完整CO分子,CO的平均吸附能处于0.990~1.602 eV之间;Sc Si@Al_(12)·7CO团簇中CO质量分数可达33.07%,有望作为CO气体过滤材料. 相似文献
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MULTIPLE-SCATTERING THEORETICAL CALCULATIONS AND ANALYSIS FOR THE ELECTRONIC STRUCTRURES OF RYDBERG STATES IN A SODIUM MOLECULE 下载免费PDF全文
Based on the independent-particle-approximation and the multiple-scattering self-consistent-field theory, we have systematically calculated the electronic struc-tures of sodium molecular Rydberg series, analysed the quantum defect μ and the electronic-vibrational interaction (i.e. dμ/dR). The influences of double excitation configuration on the Rydberg series have been discussed. The electronic structures of Rydberg states and related dynamic behavior in a sodium molecule have been eluci-dated. Our theoretical results are in fair agreement with the available experimental measurements. 相似文献
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《Surface science》1995,325(3):L421-L427
We use thermal desorption spectroscopy to estimate the adsorption energy of CO on NiO(100) to be 7.0–8.8 kcal mol−1. NEXAFS is employed to determine the orientation of the CO axis. The molecule is oriented perpendicular to the NiO(100) surface. In the present case we have resorted to angle-resolved photoelectron spectroscopy (ARUPS) to find indications that the CO molecule interacts with the surface through its carbon lone pair. The experimental analysis is in agreement with theoretical predictions that CO is held to NiO(100) mainly via electrostatic multipolar forces. 相似文献
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Chemisorption of atomic hydrogen on the Si(100)2×1 surface has been investigated in detail by using a field ion-scanning tunneling microscope (FI-STM). The results showed that the adsorption geometry changed from the 2×1 monohydride phase to the 1×1 dihydride phase with increasing exposure of hydrogen. The data of desorption of the hydrogen-saturated Si surface showed that on annealing at 670K the surface becomes highly disordered: the 1×1 dihydride structure is eliminated and the 2×1 reconstructed monohydride is also hardly to identify. When the temperature rises to as high as 730 K, the surface is domi-nated by the 2×1 structure with missing dimer rows, and some adatom chains occur on the Si substrate ler-races. We attribute the formation of these atomic chains to an epitaxial growth of Si atoms which are formed by the dissociation of SiHx (x= 1, 2, 3 or 4) compounds on the Si surface. 相似文献
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A STUDY ON THE ULTRASONIC VELOCITY AND ATTENU-ATION IN NdFeB MAGNET WITHIN THE TEMPERATURE RANGE OF 80 - 300K (Ⅱ) 下载免费PDF全文
Based on the ultrasonic measurements of an isotropic NdFeB magnet in the temperature range of 77 -300 K, it was found that the elastic parameters, such as Young's modulus E, and Poisson ratio v, change abruptly near the spin reorientation temperature Tsr. This indicates that soft mode emerges in the process of spin reorientation. Thermal hysteresis was observed during heating-up and cooling-down processes. Both Debye temperature and heat capacity were calculated, which suggests that the magnetic entropy of the Nd-sublattice is larger in easy-cone state than in easy-axis state. 相似文献