铝原子团簇Al5、Al5-和Al5+稳定结构的密度泛函理论研究

采用密度泛函理论的四种方法 :杂化密度泛函B3LYP与B3PW 91、Perdew Wang91交换与相关泛函WP91PW91、局域自旋密度近似SVWN ,研究了Al5、Al5-和Al5+ 团簇的多种可能结构 ,找到了它们稳定的结构与自旋态 ,与已有的理论结果作了比较 ,并计算了Al5-的绝热与垂直电子离解能、Al5的绝热与垂直电离势 ,同有关的实验数据比较 ,符合较好 .同时对四种密度泛函方法的计算结果作了一些比较与讨论

Density Functional Theory Study on the Stable Structures of Aluminum Cluster:Al5,Al5- and Al5+

Four methods (B3LYP, B3PW91, PW91PW91, SVWN) of density functional theory with the polarized split-valence basis sets 6-311+G(3df) have been performed to further investigate the stable structures and the spin multiplicities for Al 5, Al 5 -, and Al 5 + clusters. For each of Al 5, Al 5 -, and Al 5 + clusters five possible structures with different spin multiplicities have been investigated respectively. Some new characteristics concerning their stable structures and spin multiplicities have been found. The stable structures obtained by four DFT methods consistently are: planar C 2v-p structure with doublet state (ground state) and three-dimensional C 2v-3d structure with quartet state for neutral Al 5; planar C 2v-p structure with singlet state for anionic Al 5 - (in the sense of vibrational averaging); three-dimensional C 2v-3d structure with singlet state (ground state) and planar C 2v-p structure with triplet state for cational Al 5 +. The adiabatic and vertical election detachment energies (ADE, VDE) of anionic Al 5 -, the adiabatic and vertical ionization potentials(AIP, VIP) of neutral Al 5 have been computed using the four DFT methods respectively. The comparison between presently calculated results and available experimental data as well as the previous theoretical computations has been made. The present results are in good agreement with experimental data .The comparison among calculated results obtained by the four DFT methods are also made. For general local minima or saddle points on a potential energy surface conclusions obtained by the four DFT methods are consistent basically, but for complicated local minima or saddle points conclusions obtained by the four DFT methods are sometimes different. It needs to further study to determine which method is relatively reliable.