...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical chemistry chemical physics: PCCP >Symmetry breaking in spin-restricted Hartree-Fock solutions: the case of the C2 molecule and the N_2~+ and F_2~+ cations
【24h】

Symmetry breaking in spin-restricted Hartree-Fock solutions: the case of the C2 molecule and the N_2~+ and F_2~+ cations

机译：自旋限制性Hartree-Fock解中的对称性破缺：以C2分子以及N_2〜+和F_2〜+阳离子为例

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

We examine a spin-preserving stability of restricted Hartree-Fock (RHF) and open-shell RHF (ROHF) solutions for homonuclear diatomic species, namely the molecule C2 and the N_2~+ and F_2~+ cations, in the entire relevant range of internuclear separations. In the presence of respective singlet, doublet, or triplet instabilities we explore the implied broken-symmetry (BS) solutions and check their stability. We also address the occurrence of vanishing roots rendered by the stability problem in the case of BS solutions. Since for homonuclear diatomic species the space symmetry of the nuclear framework cannot be broken, the only possible space symmetry breaking involves either the electron charge distribution or the rotational symmetry about the internuclear axis. Such BS solutions arise primarily due to the symmetry breaking of the valence, mostly frontier, molecular orbitals, which approach atomic-type orbitals in the dissociation limit. The resulting BS RHF or ROHF solutions yield much more realistic potential energy curves (PECs) than do the symmetry-adapted (SA) solutions. For the sake of comparison, we also generated corresponding PECs using the density functional theory (DFT). Finally, we examine the role of BS molecular orbitals in post-HF correlated approaches to the many-electron problem, specifically in the computation of equilibrium properties using the coupled-cluster method with singles and doubles (CCSD) and its perturbatively corrected version for triples, the CCSD(T) method.
机译：我们研究了限制Hartree-Fock（RHF）和开壳RHF（ROHF）解决方案对同核双原子物种（即分子C2和N_2〜+和F_2〜+阳离子）在整个相关范围内的自旋保持稳定性。核间分离。在存在单重态，双重态或三重态不稳定性的情况下，我们探索隐含的对称不对称（BS）解决方案，并检查其稳定性。在BS解决方案的情况下，我们还解决了由稳定性问题导致的根消失的情况。由于对于同核双原子物质，不能破坏核骨架的空间对称性，因此唯一可能的空间对称性破坏涉及电子电荷分布或围绕核间轴的旋转对称性。此类BS解决方案的出现主要是由于价态的对称性破裂（主要是前沿的分子轨道），其在解离极限内接近原子型轨道。所得的BS RHF或ROHF解决方案比适应对称（SA）的解决方案能产生更现实的势能曲线（PEC）。为了进行比较，我们还使用密度泛函理论（DFT）生成了相应的PEC。最后，我们研究了BS分子轨道在HF后相关方法解决多电子问题中的作用，特别是在使用单打和双打耦合簇方法（CCSD）及其三重扰动校正版本的平衡特性计算中，即CCSD（T）方法。

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