Surface Science Research Centre, Department of Chemistry, University of Liverpool, Liverpool L69 3BX, UK.
J Phys Condens Matter. 2013 Sep 4;25(35):355006. doi: 10.1088/0953-8984/25/35/355006. Epub 2013 Jul 29.
As a first step to meet the challenge to calculate the electronic structure and total energy of charged states of atoms and molecules adsorbed on ultrathin insulating films supported by a metallic substrate using density functional theory (DFT), we have developed a simplified new DFT scheme that only describes the electrostatic interaction of an external charged system with a metal surface. This purely electrostatic interaction is obtained from the assumption that the electron densities of the two fragments (charged system and metal surface) are non-overlapping and by neglecting non-local exchange-correlation effects such as the van der Waals interactions between the two fragments. In addition, the response of the metal surface to the electrostatic potential from the charged system is treated to linear order, whereas the charged system is treated fully within DFT. In particular, we consider the classical perfect conductor model for the metal response, although our formalism is not limited to this approximation. To test the computational implementation of this new scheme, we have considered the case of a Na(+) cation interacting with a perfect conductor. The application of this new methodology to realistic problems involving charged systems adsorbed on insulating films supported by a metal surface are deferred to a separate following publication.
为了应对使用密度泛函理论（DFT）计算吸附在金属基底支撑的超薄绝缘膜上的原子和分子的带电态的电子结构和总能量这一挑战，我们首先开发了一种简化的新 DFT 方案，该方案仅描述了外部带电系统与金属表面的静电相互作用。这种纯粹的静电相互作用是基于假设两个片段（带电系统和金属表面）的电子密度不重叠，并忽略了非局部交换相关效应，例如两个片段之间的范德华相互作用。此外，金属表面对带电系统静电势的响应被线性化处理，而带电系统则在 DFT 中完全处理。特别是，我们考虑了金属响应的经典理想导体模型，尽管我们的形式主义并不限于此近似。为了测试这种新方案的计算实现，我们考虑了 Na(+)阳离子与理想导体相互作用的情况。将这种新方法应用于涉及吸附在金属表面支撑的绝缘膜上的带电系统的实际问题，将推迟到后续的单独出版物中。
