Department of Physics, University of Central Florida, Orlando, FL 32816, USA.
J Phys Condens Matter. 2010 Nov 24;22(46):462202. doi: 10.1088/0953-8984/22/46/462202. Epub 2010 Nov 4.
We propose a combined density-functional-theory-dynamical-mean-field-theory (DFT + DMFT) approach for reliable inclusion of electron-electron correlation effects in nanosystems. Compared with the widely used DFT + U approach, this method has several advantages, the most important of which is that it takes into account dynamical correlation effects. The formalism is illustrated through different calculations of the magnetic properties of a set of small iron clusters (number of atoms 2 ≤ N ≤ 5). It is shown that the inclusion of dynamical effects leads to a reduction in the cluster magnetization (as compared to results from DFT + U) and that, even for such small clusters, the magnetization values agree well with experimental estimations. These results justify confidence in the ability of the method to accurately describe the magnetic properties of clusters of interest to nanoscience.
我们提出了一种组合密度泛函理论-动力学平均场理论（DFT + DMFT）方法，用于在纳米系统中可靠地包含电子-电子相关效应。与广泛使用的 DFT + U 方法相比，该方法具有几个优点，其中最重要的是它考虑了动力学相关效应。该形式主义通过对一组小铁团簇（原子数 2 ≤ N ≤ 5）的磁性的不同计算进行说明。结果表明，动力学效应的包含导致团簇磁化强度降低（与 DFT + U 的结果相比），并且即使对于如此小的团簇，磁化强度值也与实验估计值很好地吻合。这些结果证明了该方法能够准确描述对纳米科学感兴趣的团簇的磁性的能力。
