title: A theoretical investigation of hyperpolarizability for small Ga(n)As(m) (n + m = 4-10) clusters.
abstract: In this paper, the second and third order polarizabilities of small Ga(n)As(m) (n + m=4-10) clusters are systematically investigated using the time dependent density functional theory (TDDFT)6-311+G* combined with the sum-over-states method (SOSTDDFT6-311+G*). For the static second order polarizabilities, the two-level term (beta(vec.2)) makes a significant contribution to the beta(vec) for all considered Ga(n)As(m) clusters except for the Ga3As4 cluster. And, for the static third order polarizabilities, the positive channel (gamma(II)) makes a larger contribution to gamma(tot) than the negative channel (gamma(I)). Similar to the cubic GaAs bulk materials, the small Ga(n)As(m) cluster assembled materials exhibit large second order (1 x 10(-6) esu) and third order susceptibilities (5 x 10(-11) esu). The dynamic behavior of beta(-2omega; omega, omega) and gamma(-3omega; omega, omega, omega) show that the small Ga(n)As(m) cluster will be a good candidate of nonlinear optical materials due to the avoidance of linear resonance photoabsorption.
authors.affiliation: Fujian Institute of Research on the Structure of Matter, State Key Laboratory of Structural Chemistry, The Graduate School of the Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.
authors.forename: Y-Z
authors.initials: YZ
authors.lastname: Lan
authors.forename: W-D
authors.initials: WD
authors.lastname: Cheng
authors.forename: D-S
authors.initials: DS
authors.lastname: Wu
authors.forename: J
authors.initials: J
authors.lastname: Shen
authors.forename: S-P
authors.initials: SP
authors.lastname: Huang
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Gong
authors.forename: F-F
authors.initials: FF
authors.lastname: Li