Reimers Jeffrey R, Solomon Gemma C, Gagliardi Alessio, Bilić Ante, Hush Noel S, Frauenheim Thomas, Di Carlo Aldo, Pecchia Alessandro
School of Chemistry, The University of Sydney, NSW 2006, Australia.
J Phys Chem A. 2007 Jul 5;111(26):5692-702. doi: 10.1021/jp070598y. Epub 2007 May 27.
A review is presented of the nonequilibrium Green's function (NEGF) method "gDFTB" for evaluating elastic and inelastic conduction through single molecules employing the density functional tight-binding (DFTB) electronic structure method. This focuses on the possible advantages that DFTB implementations of NEGF have over conventional methods based on density functional theory, including not only the ability to treat large irregular metal-molecule junctions with high nonequilibrium thermal distributions but perhaps also the ability to treat dispersive forces, bond breakage, and open-shell systems and to avoid large band lineup errors. New results are presented indicating that DFTB provides a useful depiction of simple gold-thiol interactions. Symmetry is implemented in DFTB, and the advantages it brings in terms of large savings of computational resources with significant increase in numerical stability are described. The power of DFTB is then harnessed to allow the use of gDFTB as a real-time tool to discover the nature of the forces that control inelastic charge transport through molecules and the role of molecular symmetry in determining both elastic and inelastic transport. Future directions for the development of the method are discussed.
本文综述了一种非平衡格林函数（NEGF）方法“gDFTB”，该方法采用密度泛函紧束缚（DFTB）电子结构方法来评估单分子的弹性和非弹性传导。本文重点关注NEGF的DFTB实现相对于基于密度泛函理论的传统方法可能具有的优势，这不仅包括处理具有高非平衡热分布的大型不规则金属 - 分子结的能力，还可能包括处理色散力、键断裂和开壳层系统以及避免大的能带排列误差的能力。文中给出的新结果表明，DFTB能对简单的金 - 硫醇相互作用给出有用的描述。DFTB中实现了对称性，并描述了它在大幅节省计算资源以及显著提高数值稳定性方面所带来的优势。接着利用DFTB的强大功能，将gDFTB用作实时工具，以揭示控制分子中非弹性电荷传输的力的性质以及分子对称性在确定弹性和非弹性传输中的作用。文中还讨论了该方法未来的发展方向。
