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采用密度泛函理论(DFT)中的杂化密度泛函B3LYP方法,在6-311G(d)基组的水平上研究了Ca2Sin(n=1~9)团簇的平衡几何结构、稳定性与光谱性质。结构优化表明:Ca2Sin团簇的基态绝大多数为立体结构(除了n=1,2)。在获得的最低能量结构基础上计算并分析了掺杂团簇的平均结合能、二阶能量差分、分裂能、能隙与光谱性质与团簇尺寸的变化关系,计算结果发现:Ca原子的掺入使得体系的化学稳定性降低,Ca2Si5,Ca2Si7与Ca2Si9是幻数结构。从光谱性质分析来看,Ca2Si5团簇与Ca2Si9团簇的红外较强吸收峰的个数较多,而Ca2Si7团簇的红外较强吸收峰的个数则较少;Ca2Si5团簇的拉曼只有一个较强峰值且位于低频段内,Ca2Si7团簇与Ca2Si9团簇的拉曼较强峰的个数较多。
The equilibrium geometry of Ca2Sin (n = 1 ~ 9) clusters was studied at the level of 6-311G (d) basis set by hybrid density functional theory B3LYP in density functional theory (DFT) Spectral properties. Structural optimization shows that most of the ground states of Ca2Sin clusters are stereostructures (except n = 1,2). Based on the obtained lowest energy structure, the average binding energy, the second order energy difference, the splitting energy, the energy gap and the spectral properties of the doped clusters were calculated and analyzed. The results showed that Ca atoms doped Into the chemical stability of the system to reduce, Ca2Si5, Ca2Si7 and Ca2Si9 is a magic number structure. From the analysis of spectral properties, Ca2Si5 clusters and Ca2Si9 clusters have more infrared absorption peaks, while Ca2Si7 clusters have fewer infrared absorption peaks. Ca2Si5 clusters have only strong Raman peaks A strong peak and located in the low frequency band, Ca2Si7 cluster and Ca2Si9 cluster Raman strong peak number more.