title: Understanding the structural transformation, stability of medium-sized neutral and charged silicon clusters.
abstract: The structural and electronic properties for the global minimum structures of medium-sized neutral, anionic and cationic Sin(μ) (n = 20-30, μ = 0, -1 and +1) clusters have been studied using an unbiased CALYPSO structure searching method in conjunction with first-principles calculations. A large number of low-lying isomers are optimized at the B3PW91/6-311 + G* level of theory. Harmonic vibrational analysis has been performed to assure that the optimized geometries are stable. The growth behaviors clearly indicate that a structural transition from the prolate to spherical-like geometries occurs at n = 26 for neutral silicon clusters, n = 27 for anions and n = 25 for cations. These results are in good agreement with the available experimental and theoretical predicted findings. In addition, no significant structural differences are observed between the neutral and cation charged silicon clusters with n = 20-24, both of them favor prolate structures. The HOMO-LUMO gaps and vertical ionization potential patterns indicate that Si22 is the most chemical stable cluster, and its dynamical stability is deeply discussed by the vibrational spectra calculations.
authors.affiliation: Department of Optoelectronic Science &Technology, College of Science, Shaanxi University of Science &Technology, Xian, 710021, China.
authors.forename: Li Ping
authors.initials: LP
authors.lastname: Ding
authors.affiliation: Department of Optoelectronic Science &Technology, College of Science, Shaanxi University of Science &Technology, Xian, 710021, China.
authors.forename: Fang Hui
authors.initials: FH
authors.lastname: Zhang
authors.affiliation: Department of Physics, Nanyang Normal University, Nanyang, 473061, China.
authors.forename: Yong Sheng
authors.initials: YS
authors.lastname: Zhu
authors.affiliation: Department of Physics, Nanyang Normal University, Nanyang, 473061, China.|Beijing Computational Science Research Center, Beijing, 100084, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Lu
authors.affiliation: Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065, China.
authors.forename: Xiao Yu
authors.initials: XY
authors.lastname: Kuang
authors.affiliation: Beijing Computational Science Research Center, Beijing, 100084, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Lv
authors.affiliation: Department of Optoelectronic Science &Technology, College of Science, Shaanxi University of Science &Technology, Xian, 710021, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Shao