论文标题
应用于异质原子键解离的近似密度矩阵函数
Approximate density matrix functionals applied to hetero-atomic bond dissociation
论文作者
论文摘要
类似于LIH的两轨两电子双原子模型用于研究确切的löwdinshull与近似hartree-fock-bogoliubov和baerends-buijse-buijse-buijse-buijse-buijse密度矩阵函数的差异。如果发生均种均质解离（每个原子上的一个电子），由于Hartree-Fock组件（有利于部分电荷转移）和强相关组件（hampers hampers电荷转移），大约功能无法产生正确的能量。确切的功能能够通过执行粘合和抗抗轨道的等值分布来生成物理上正确的答案。此外，由于强相关组件阻碍电荷转移，大概功能还存在正确描述杂解解离（一个原子上的两个电子）方面的问题。在这项工作中，我们提出了一个新方案，其中通过添加一个Lagrange乘法器来避免使用近似功能的均利性解离问题，从而强制执行键合和抗抗方向轨道的等值分布。研究结果的基于符号的性质意味着它们最有可能转移到其他情况下，其中人们使用近似的单粒子方法与对称粒子孔校正因子结合使用。
A two-orbital two-electron diatomic model resembling LiH is used to investigate the differences between the exact Löwdin-Shull and approximate Hartree-Fock-Bogoliubov and Baerends-Buijse density matrix functionals in the medium- to long-distance dissociation region. In case of homolytic dissociation (one electron on each atom), the approximate functionals fail to generate the correct energy due to a compromise between the Hartree-Fock component (which favors partial charge transfer) and the strong correlation component (which hampers charge transfer). The exact functional is able to generate the physically correct answer by enforcing the equi-charge distribution of the bonding and antibonding orbitals. Besides, the approximate functionals also have issues in correctly describing heterolytic dissociation (two electrons on one atom) due to the strong correlation component hampering charge transfer. In this work, we propose a new scheme in which the homolytic dissociation problem for approximate functionals is avoided by adding a Lagrange multiplier that enforces equi-charge distribution of the bonding and antibonding orbitals. The symmety based nature of the findings implies that they are most likely transferable to other cases in which one uses an approximate one-particle method in conjunction with a symmetrical particle-hole correction factor.
