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arXiv 0704.1572cond-mat.mtrl-sci
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近似自相互作用修正方案的交换参数

Exchange parameters from approximate self-interaction correction scheme

A. Akande, S. Sanvito

摘要:

通过计算对局域交换和关联泛函至关重要的一些典型材料的交换相互作用,对密度泛函理论的近似原子自相互作用修正(ASIC)方法进行了检验. ASIC的总能量计算映射到海森堡成对相互作用和交换常数J与其他方法得到的比较。一般来说,ASIC方案大大提高了能带结构,几乎所有的情况下,调查类似密切可用的光发射数据。相比之下,交换参数的结果不太令人满意。尽管ASIC对于磁性源自半填充带的系统表现得相当好,但对于其他情况,它也遇到了与LDA类似的问题。特别是交换常数仍然被高估。这反映了交换能量和相关能量之间的微妙相互作用,ASIC没有捕获。

英文摘要:

The approximate atomic self-interaction corrections (ASIC) method to density functional theory is put to the test by calculating the exchange interaction for a number of prototypical materials, critical to local exchange and correlation functionals. ASIC total energy calculations are mapped onto an Heisenberg pair-wise interaction and the exchange constants J are compared to those obtained with other methods. In general the ASIC scheme drastically improves the bandstructure, which for almost all the cases investigated resemble closely available photo-emission data. In contrast the results for the exchange parameters are less satisfactory. Although ASIC performs reasonably well for systems where the magnetism originates from half-filled bands, it suffers from similar problems than those of LDA for other situations. In particular the exchange constants are still overestimated. This reflects a subtle interplay between exchange and correlation energy, not captured by the ASIC.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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