An inversion technique for the calculation of embedding potentials.
An inversion technique for the calculation of embedding potentials.
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用于计算嵌入势的反演技术。
DOI：
10.1063/1.3007987
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
A. Aguado
中科院分区：
文献类型：
--
作者：
O. Roncero;M. P. Lara;Pablo Villarreal;F. Flores;J. Ortega;M. Paniagua;A. Aguado
提出了一种新的包含大系统局部相关的嵌入方法。在这种方法中，整个系统的密度，通过密度泛函理论的方法计算，被划分为两部分，一部分对应于感兴趣的子系统，其余部分对应于环境。在第二步中，使用密度差引起的自排斥作为驱动力迭代获得嵌入电位，其形式与Zhao等人提出的形式相似。Rev. A 50, 2138(1994)]，以获得“精确的”交换相关函数。将这种势加到Fock方程中以建立局域分子轨道，这些局域分子轨道进一步用于在感兴趣的子系统中包含局域电子相关。该方法是对先前由Wesolowski和Washell首先提出的基于dft的嵌入方法的替代方法。理论物理。[J] .化学学报，1997,8050(1993)]。化学。并适用于金属扩展系统，该系统使用密度泛函来描述对嵌入势的动能贡献，其精确形式已在文献中得到了很大程度的处理，本文将讨论其关键作用。该方法应用于氢链及其与H(2)的范德华相互作用。所得结果与在整个系统上进行的精确计算结果吻合得很好，表明所提出的方法是在大系统中引入相关的一条很有前途的途径。
A new embedding method to include local correlation in large systems is proposed. In this method the density of the whole system, calculated via density functional theory approaches, is partitioned in two pieces, one corresponding to the subsystem of interest and the rest to the environment. In the second step, an embedding potential is obtained iteratively using as a driving force the self-repulsion due to the density difference, in a similar form as proposed by Zhao et al. [Phys. Rev. A 50, 2138 (1994)], to obtain the "exact" exchange-correlation functional. Such potential is added to the Fock equation to build the localized molecular orbitals which are further used to include the local electronic correlation in the subsystem of interest. This method is an alternative to the previous DFT-based embedding methods first proposed by Wesolowski and Washell [J. Phys. Chem. 97, 8050 (1993)] and after enhanced by Govind et al. [J. Chem. Phys. 110, 7677 (1999)] and adapted to metal extended systems, which use density functionals to describe the kinetic energy contribution to the embedding potential, whose precise form has been largely treated in the literature and its crucial role is discussed here. The method is applied to hydrogen chains and its van der Waals interaction with H(2). The results obtained are in very good agreement with exact calculations performed on the whole system, which demonstrates that the method proposed is a very promising route to introduce correlation in large systems.