Calculation of Zn, Cd, Hg adsorption on graphene with incremental CCSD(T) and range-separated hybrid DFT*

At the hand of the adsorption of the metal atoms Zn, Cd and Hg on a graphene sheet, we propose a combination of range-separated hybrid density-functional theory in combination with the incremental scheme in localised orbitals and extrapolation procedures for the description of this type of extended systems. Using only dispersion terms for the long-range part, we were able to obtain results comparable to incremental coupled-cluster calculations with singles, doubles and perturbative triples (CCSD(T)). Repulsive three-centre increments reduce the overall correlation contribution to the binding energy by 20 %.

针对锌（Zn）、镉（Cd）、汞（Hg）金属原子在石墨烯片层上的吸附体系，我们提出将长程分离杂化密度泛函理论（range-separated hybrid density-functional theory）与定域轨道增量方案（incremental scheme in localised orbitals）以及用于描述这类延展体系的外推方法（extrapolation procedures）相结合。仅采用长程部分的色散项（dispersion terms）进行计算，即可获得与单双激发并考虑微扰三重激发的耦合簇计算（coupled-cluster calculations with singles, doubles and perturbative triples，CCSD(T)）相当的结果。排斥性三中心增量可将结合能的总相关贡献降低20%。