Self-consistent-charge density-functional tight-binding method for simulations of complex materials properties
Self-consistent-charge density-functional tight-binding method for simulations of complex materials properties
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DOI：
10.1103/physrevb.58.7260
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发表时间：
1998-09-15
影响因子：
3.7
通讯作者：
Seifert, G
中科院分区：
文献类型：
--
作者：
Elstner, M;Porezag, D;Seifert, G
我们概述的紧束缚（TB）的方法，以提高总能量，力和可转移性的扩展的细节。该方法是基于密度泛函理论（DFT）中的Kohn-Sham总能量相对于电荷密度波动的二阶展开。零阶方法相当于一个常见的标准非自洽（TB）计划，而在二阶透明，无参数，易于计算的广义哈密顿矩阵元素的表达式可以导出。这些都是修改的自洽重新分配的Mulliken收费（SCC）。除了通常的“能带结构”和剪切范围排斥条款的最终近似Kohn-Sham能量还包括电荷波动之间的库仑相互作用。在大的距离，这说明了两个点电荷之间的长程静电力，并且如果电荷位于同一个原子上，则近似包括给定原子的自相互作用贡献。我们应用新的SCC计划的问题，在非SCC标准TB方法的缺陷变得明显。因此，我们大大提高了可转移性。
We outline details about an extension of the tight-binding (TB) approach to improve total energies, forces, and transferability. The method is based on a second-order expansion of the Kohn-Sham total energy in density-functional theory (DFT) with respect to charge density fluctuations. The zeroth order approach is equivalent to a common standard non-self-consistent (TB) scheme, while at second order a transparent, parameter-free, and readily calculable expression for generalized Hamiltonian matrix elements may be derived. These are modified by a self-consistent redistribution of Mulliken charges (SCC). Besides the usual "band structure" and shea-range repulsive terms the final approximate Kohn-Sham energy additionally includes a Coulomb interaction between charge fluctuations. At large distances this accounts for long-range electrostatic forces between two point charges and approximately includes self-interaction contributions of a given atom if the charges are located at one and the same atom. We apply the new SCC scheme to problems where deficiencies within the non-SCC standard TB approach become obvious. We thus considerably improve transferability.