中文摘要：

本文采用基于密度泛函理论的第一性原理平面波赝势方法研究了双轴应力作用下锂原子吸附硅烯的结构及其稳定性.计算结果表明,在拉应力和一定的压应力作用下,锂吸附的硅烯体系基本保持原有的结构.而当更大的压应力作用时,硅烯产生了向锂原子方向凸起的结构变化,所得到的体系的总能也有明显地下降.本文通过对各种应力下的硅烯声子谱的计算,分析了在压应力作用下锂吸附的硅烯结构不稳定的原因.

英文摘要：

Structure and stability of the Li-adsorbed silicene under a biaxial strain are studied by using the first-principles plane-wave pseudopotential method based on the density functional theory. Results show that Li-adsorbed silicenes keep their original configurations basically when the tensile and certain compressive strains are applied, while the silicene plane bulges towards the Li atom when a larger compressive strain is applied, and the total energy of the corresponding system becomes distinctly lower. We also calculate the phonon spectra of the silicene under various strains, and analyze the reason why the Li-adsorbed silicene is unstable under the compressive strain.