Resonating broken-symmetry approach to biradicals and polyradicals
Resonating broken-symmetry approach to biradicals and polyradicals
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DOI：
10.1002/qua.21203
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发表时间：
2006
影响因子：
2.2
通讯作者：
R. Takeda;S. Yamanaka;K. Yamaguchi
中科院分区：
文献类型：
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作者：
R. Takeda;S. Yamanaka;K. Yamaguchi
我们提出了一种强关联电子系统的共振破缺对称性方法。这是使用对称破缺的Hartree-Fock(HF)参考的非正交组态相互作用(CI)。我们已将其应用于氢分子、线性氢链模型体系和氟分子。众所周知，S=1/2双自由基体系的自旋污染可以通过两个自旋不受限制的高频组态的共振来消除。相比之下，需要更多的构型才能在多自由基体系中完美地进行自旋投影。讨论了RBS分子轨道(MO)方法对金属团簇等更复杂体系的适用性。©2006威利期刊公司Int J Quantum Chem，2006
We present a resonating broken-symmetry (RBS) approach for strongly correlated electron systems. This is a nonorthogonal configuration interaction (CI) using symmetry-broken Hartree–Fock (HF) references. We have applied it to the hydrogen molecule, linear hydrogen chain model systems, and to the fluorine molecule. As is known, spin contamination of biradical system with S = 1/2 can be removed by taking the resonance of two spin-unrestricted HF (UHF) configurations. In contrast, more configurations were required to do spin projections perfectly in polyradical systems. The implications of the computational results are discussed in relation to the applicability of the RBS molecular orbital (MO) approach to more complex systems, such as metal clusters. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006