...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemical Physics: A Journal Devoted to Experimental and Theoretical Research Involving Problems of Both a Chemical and Physical Nature >Second-order Moller-Plesset perturbation theory for computing molecular-field splitting: application to the S2p_(3/2) level in C_2H_(2n+1)SF_5, n = 0, 1, and 2
【24h】

Second-order Moller-Plesset perturbation theory for computing molecular-field splitting: application to the S2p_(3/2) level in C_2H_(2n+1)SF_5, n = 0, 1, and 2

机译：计算分子场分裂的二阶Moller-Plesset微扰理论：在C_2H_（2n + 1）SF_5中的S2p_（3/2）水平上的应用，n = 0、1和2

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

High-resolution molecular X-ray photoelectron spectra of second-row atoms may reveal broadening or even splitting of the 2p_(3/2) peak as compared to the 2p_(1/2) component of the spectrum. This splitting reflects the lifted degeneracy of atomic 2p orbitals at sites of less than cubic symmetry and is referred to as molecular-field splitting (MFS). The prospect of using second-order Moller-Plesset theory (MP2) for ab initio calculation of the MFS for sulfur 2p_(3/2) levels is examined. This method is subsequently applied to compute the MFS in ethynyl, ethenyl, and ethyl sulfur penta-fluoride, resulting in values of 80, 116 and 121 meV, respectively. The initial-state contribution to the splitting is analyzed in terms of asymmetry in the electron density at sulfur, on the one hand, and in terms of the sulfur-ligand overlap density and electron density at the groups bonded to sulfur, on the other. At the Koopman's theorem level of theory, the main source of splitting in the title compounds is found to be s-d hybridization of sulfur. At post-SCF levels of theory, core-valence electron correlation contributes substantially to the MFS, in proportion to the occupational asymmetry of the S3p shell. The realization that mixing of sulfur atomic orbitals of the same parity may add important contributions to the electric-field gradient at the core, resolves the observed diversity in the relative importance of core-valence electron correlation between different classes of sulfur compound.
机译：第二行原子的高分辨率分子X射线光电子能谱显示与谱图的2p_（1/2）分量相比，2p_（3/2）峰变宽甚至分裂。这种分裂反映了原子2p轨道在小于立方对称性的位点上提升的简并性，被称为分子场分裂（MFS）。研究了使用二阶Moller-Plesset理论（MP2）从头算起硫2p_（3/2）的MFS的前景。该方法随后应用于计算乙炔基，乙烯基和乙基硫五氟化物中的MFS，分别得到80、116和121 meV的值。一方面，根据硫处的电子密度的不对称性，另一方面根据硫-配体重叠密度和与硫键合的基团上的电子密度，分析了对分裂的初始态贡献。在理论的考夫曼定理水平上，发现标题化合物分裂的主要来源是硫的s-d杂交。在后SCF的理论水平上，与S3p壳的职业不对称性成比例，核心价电子相关性对MFS贡献很大。认识到同等硫原子轨道的混合可能会增加核心处的电场梯度，从而解决了不同类别的硫化合物之间的核心价电子相关的相对重要性所观察到的多样性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号