The Theoretical Study Of Krypton Adsorption On The Graphene Surface

Weak interactions play an important role in several scientific areas, such as chemistry, biology and physics. By accurately accounting for the weak interaction can acquire basis information on the structure, energy, and dynamics which is related to the target system, and this issue has become a hot and difficult spot in scientific fields.A reliable theoretical description of the weak interaction is one of the challenges of contemporary computational chemistry. At present, there are two models, Slab and Cluster, is used to study the gas-solid system. Slab model uses periodic boundary conditions to simulate solid surface, and this model mostly applies to the LDA-DFT and GGA-DFT density functional method. Cluster model uses finite unit molecule or atom clusters to simulate the solid surface, and its advantage is able to apply the high-precision ab initio method in quantum chemistry. The former, namely Slab model, is often used to study the intermolecular interaction of rare gas adsorption on the graphene surface.Slab model combined with LDA-/GGA-DFT is usually used to study the physical adsorption of Rg/Graphene system. It is well known that both LDA and GGA fail in describing weak interaction owing to its own deficiency in long-range interaction. This work employs the high-precis ion ab initio and the improved DFT methods to study Kr/Graphene system. Coronene is used to simulate the micro-surface of graphene in order to study the interaction mechanism of Kr/Graphene system. The results of this study are as follows:1. By studying the Rg/Benzene system with many different methods, implies that second M(?)ller-Plesset perturbation theory (MP2) and MPW2PLYD have a good agreement with experiment. Therefore, it can accurately describe the interaction of rare gas atom with benzene-based conjugate system.2. By a series of tests on structure manifest that coronene is the proper one to model the graphene surface.3. The results of MP2and MPW2PLYPD show that Kr prefers to adsorb on the high-coordination Hollow site at the graphene surface, unlike adsorbing on the low-coordination Top site at the metal surface.4. Krypton atom prefers to adsorb on the high-coordination hollow site of graphene surface mainly attributes to the low density of electron, that means small repulsion. Therefore, when krypton atom closes to the hollow site, the region plays a acceptor-like character.