The geometries, adsorption energies, and electronic structures of Cs, Sr, and Ag atoms on matrix graphite surface with point defects were calculated and analyzed using the density functional theory (DFT) and the Perdew–Burke–Ernzerhof (PBE) formulation of the generalized gradient approximation (GGA). Three different types of point defects, i.e., single vacancy and “bridge” and “spiro” interstitials are considered using approximate van der Waals (vdW) correction methods. The results of adsorption energies show that the metal fission products of Cs, Sr, and Ag are more stable on single vacancy defects than “bridge” or “spiro” interstitial defects. This is further confirmed by the analysis of electronic structures, such as charge density difference (CDD) and density of state (DOS). All these results indicate that dangling bonds play an important role in the adsorption behaviors of metallic fission products on matrix graphite.

中文翻译：

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缺陷基质石墨上Cs / Sr / Ag吸附的DFT研究

使用密度泛函理论（DFT）和广义的Perdew-Burke-Ernzerhof（PBE）公式，计算并分析了具有点缺陷的基质石墨表面上Cs，Sr和Ag原子的几何形状，吸附能和电子结构。梯度近似（GGA）。使用近似范德华（vdW）校正方法考虑了三种不同类型的点缺陷，即单空位和“桥”和“螺”间隙。吸附能的结果表明，Cs，Sr和Ag的金属裂变产物在单空位缺陷上比“桥”或“螺”间隙缺陷更稳定。通过分析电子结构，例如电荷密度差（CDD）和状态密度（DOS），可以进一步证实这一点。