掺Be硼团簇BeBn^0/–(n=10—15)的基态结构和性质  

Ground state structures and properties of Be atom doped boron clusters BeBn^0/-(n=10-15)

作　　者：李世雄 陈德良 张正平 隆正文 Li Shi-Xiong;Chen De-Liang;Zhang Zheng-Ping;Long Zheng-Wen(School of Physics and Electronic Science,Guizhou Education University,Guiyang 550018,China;College of Big Data and Information Engineering,Guizhou University,Guiyang 550025,China;College of Physics,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州师范学院物理与电子科学学院,贵阳550018 [2]贵州大学大数据与信息工程学院,贵阳550025 [3]贵州大学物理学院,贵阳550025

出　　处：《物理学报》2020年第19期54-65,共12页Acta Physica Sinica

基　　金：国家自然科学基金青年基金基金(批准号:11804065);中央引导地方科技发展专项资金(批准号:黔科中引地[2019]4012号)资助的课题~~

摘　　要：基于密度泛函理论结合粒子群优化算法程序CALYPSO研究了掺Be硼团簇BeBn0/–(n=10—15)的基态几何结构;然后采用密度泛函理论分析了最低能量结构的电子结构、极化率、红外光谱、紫外可见光谱特性.研究结果表明:BeB100/–,BeB11-,BeB120/-,BeB14-具有平面或准平面结构;BeB11,BeB13,BeB13-,BeB14分别具有半三明治结构、圆锥结构、笼型结构、压扁的管状结构;BeB150/-呈现手性对称结构.自然布居分析(NPA)表明掺杂Be原子将电子转移给硼原子.团簇的平均结合能分析可得,阴离子比相应中性团簇的稳定性强;另外,随着n的增加,中性和阴离子团簇的稳定性增强.准平面结构BeB10,BeB11-,BeB12团簇的适应性自然密度划分(AdNDP)分析表明,s键促进了整个分子的稳定性,多中心π键进一步稳定了整个分子;另外,这三个团簇满足6个π电子Hückel规则(4m+2),具有芳香性.极化率分析可得,平面或准平面结构的每个原子的平均极化率大于其它结构,说明平面或准平面结构的电子离域效应较大;BeB13-,BeB14-具有较大的第一超极化率,说明具有较强的非线性光学响应.红外光谱分析表明这些团簇具有不同的特征峰,可用于鉴别这些结构;闭壳层结构团簇的紫外可见光谱在可见光波段都有吸收峰,开壳层结构团簇的紫外可见光谱在红外光波段都有吸收峰.A theoretical study of geometrical structures and electronic properties of Be atom doped boron clusters BeBn0/-(n=10-15)is performed using the CALYPSO approach for the global minimum search followed by density functional theory calculations.It is found that the global minima obtained for the BeB100/-,BeB11-,BeB120/-,and BeB14-clusters correspond to the quasi-planar or planar structures.However,the global minima obtained for the BeB11,BeB13,BeB13-,BeB14 clusters correspond to the half-sandwich,cone,cage,squashed tubular structures,respectively.Interestingly,both the neutral and anionic BeB150/-clusters have the axially chiral isomers which are chiral with degenerate enantiomers.Natural population analyses reveal that partial charge on Be atom transfer to boron atoms.The average binding energy values of BeBn0/-(n=10-15)indicate that anionic clusters are overall more stable than the corresponding neutral ones,and both neutral and anionic clusters show the same trend that the stability increases gradually with the increase of B atoms number n.Chemical bonding analyses of closed-shell BeB10,BeB11-,BeB12 clusters reveal that theσbonds stabilize whole molecular skeleton,and delocalizedπbonds render the structure more stable.Furthermore,the three quasiplanar closed-shell clusters possess 3 delocalizedπbonds,which quite surprisingly follow the 4 m+2 H(u|")ckel rule for aromaticity.Average polarizability of single atom for each quasi-planar or planar structure is larger than other structures,it indicates that quasi-planar or planar structure has stronger electron delocalization.Specifically,BeB13-and BeB14-with large first static hyperpolarizability can lead to the remarkable NLO response.The calculated spectra indicate that BeBn0/-(n=10-15)have the meaningful characteristic peaks which can be compared with future experimental values.Our work enriches the database of geometrical structures of doped boron clusters and can provide much insight into the new doped boron clusters.

关 键 词：掺Be硼团簇 基态结构 电子结构 光谱 

分 类 号：O641.4[理学—物理化学]