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Nghiên cứu so sánh cấu trúc, độ bền của cluster silic pha tạp SinM (M là Sc, Y; n = 1-10) bằng phương pháp hóa học lượng tử

Nguyễn Quốc Cường, Nguyễn Duy Phi, Vũ Thị Ngân, Nguyễn Phi Hùng, Nguyễn Tiến Trung

Abstract


Geometrical structures and stabilities of the doped SinM (M = Sc, Y; n = 1-10) clusters were thoroughly investigated using density functional theory. The geometrical optimizations and harmonic frequency calculations were performed at the B3P86/DGDZVP level of theory. We found that the doped clusters SinSc, SinY are less symmetrical than the pure Sin+1 clusters. The ground states of SinM with n = 2-10 favor the low-spin state (doublet). Analysis of the growth mechanism found that the substitution rule is strictly obeyed as n £ 6 while it is not true for the rest. As n > 6, the two dopants modified the structures of silicon clusters in various ways leading to many low-lying isomers. The metal atoms can be substituted to either a pentagonal bipyramidal structure or a trigonal prism or even formed a new structure. Analysis of energetic parameters including average binding energy, fragmentation energy, second-order difference of energy, HOMO-LUMO gap indicates that the stability of doped clusters are in general lower than the corresponding pure Si clusters.

Keywords. Sc-doped Si cluster, Y-doped Si cluster, B3P86, stability of cluster.

Keywords


Geometrical structures and stabilities of the doped SinM (M = Sc, Y; n = 1-10) clusters were thoroughly investigated using density functional theory. The geometrical optimizations and harmonic frequency calculations were performed at the B3P86/DGDZVP leve

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