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基于第一性原理的自洽场密度泛函理论(DFT)和广义梯度近似(GGA),利用缀加平面波加局域轨道(APW+lo)近似方法,建立了五层层晶超原胞模型,模拟了GaAs(110)表面结构和单个Xe原子在其表面的吸附.利用牛顿动力学方法,对GaAs(110)表面原子构形的弛豫和Xe原子在GaAs(110)表面的吸附进行了计算.从三种不同的初始构形出发,即Xe原子分别在Ga原子的顶位,As原子的顶位以及桥位,都发现Xe原子位于桥位时体系能量最低.由此,认为Xe原子在GaAs(110)表面的吸附位置在桥位,并且发现吸附Xe原子后GaAs(110)表面有趋向于理想表面的趋势,表面重构现象趋于消失,表面原子间键长有一定的恢复,这与理论预言相符合.
Based on the first-principle self-consistent field density functional theory (DFT) and generalized gradient approximation (GGA), a five-layer model of superlattice cell was established by using the APW + lo approximation method. , The adsorption of GaAs (110) surface structure and a single Xe atom on its surface has been simulated.The relaxation of the atomic configuration of GaAs (110) surface and the adsorption of Xe atoms on GaAs (110) surface have been studied by Newtonian dynamics Starting from three different initial configurations, ie, the Xe atom is at the top of Ga atom, the top of As atom and the bridge site respectively, it is found that the energy of the system is the lowest when the Xe atom is located at the bridge site. Therefore, it is considered that the Xe atom The adsorption sites on the GaAs (110) surface are at the bridge sites, and the adsorption of Xe atoms on GaAs (110) surface tends to the ideal surface. The surface reconstruction tends to disappear and the bond length of the surface atoms recover to some extent. This is in line with theoretical predictions.