Division of Natural Sciences, Keuka College, Keuka Park, New York 14478, USA.
J Chem Phys. 2013 Jun 21;138(23):234310. doi: 10.1063/1.4810870.
Carbon 1s photoelectron spectra for 2-butyne (CH3C≡CCH3) measured in the photon energy range from threshold to 150 eV above threshold show oscillations in the intensity ratio C2,3/C1,4. Similar oscillations have been seen in chloroethanes, where the effect has been attributed to EXAFS-type scattering from the substituent chlorine atoms. In 2-butyne, however, there is no high-Z atom to provide a scattering center and, hence, oscillations of the magnitude observed are surprising. The results have been analyzed in terms of two different theoretical models: a density-functional model with B-spline atom-centered functions to represent the continuum electrons and a multiple-scattering model using muffin-tin potentials to represent the scattering centers. Both methods give a reasonable description of the energy dependence of the intensity ratios.
对于 2-丁炔（CH3C≡CCH3），在光子能量范围从阈值到阈值以上 150 eV 进行的碳 1s 光电子能谱测量显示出 C2,3/C1,4 强度比的振荡。在氯乙烷中也观察到了类似的振荡，其中这种效应归因于取代氯原子的 EXAFS 型散射。然而，在 2-丁炔中，没有高 Z 原子提供散射中心，因此观察到的幅度的振荡是令人惊讶的。结果已经根据两种不同的理论模型进行了分析：一个带有 B 样条原子中心函数的密度泛函模型来表示连续电子，以及一个使用 muffin-tin 势来表示散射中心的多散射模型。这两种方法都对强度比的能量依赖性给出了合理的描述。
