Is the divide-and-conquer Hartree-Fock method valid for calculations of delocalized systems?
Is the divide-and-conquer Hartree-Fock method valid for calculations of delocalized systems?
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DOI：
10.1080/00268970701642267
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发表时间：
2007-01-01
影响因子：
1.7
通讯作者：
Nakai, Hiromi
中科院分区：
文献类型：
--
作者：
Akama, Tomoko;Fujii, Atsuhiko;Nakai, Hiromi
最近，我们将Yang的分治法（DC）应用于Hartree-Fock （HF）和杂化密度泛函理论，并评估了其在计算键交替多烯链中的可靠性。本文通过比较键交替多烯链和离域均匀多烯链的结果，研究了DC-HF方法中HF交换相互作用的切断行为。由于均匀多烯链的电子结构离域，均匀多烯链的截止误差比键交替链大得多。我们还估计了直流格式中截止误差的指数衰减系数，并将其与实数空间单粒子密度矩阵的指数衰减系数进行了比较，该矩阵可以用绝缘子极限带隙表示。可以得出结论，通过采用与带隙相对应的适当缓冲半径，可以将DC-HF方法得到的截止误差减小到任意大小。
Recently, we applied Yang's divide-and-conquer (DC) method to the Hartree-Fock (HF) and hybrid density functional theories and assessed its reliability in calculations of bond-alternating polyene chains. In this paper, we investigate the cut-off behaviour of the HF exchange interaction in the DC-HF method by comparing the results of bond-alternating polyene chains with those of more delocalized uniform polyene chains. The cut-off error of the uniform chain is much larger than that of the bond-alternating chain because of the delocalized electronic structure of the uniform polyene chain. We also estimate the exponential decay coefficient of the cut-off error in the DC scheme and compare it with that of the real-space one-particle density matrix, which can be represented by the band gap in the insulator limit. It can be concluded that the cut-off derived from the DC-HF method can be reduced to an arbitrary magnitude of error by adopting an appropriate buffer radius corresponding to the band gap.