Li4团簇光吸收谱的含时密度泛函理论研究  

The study of photoabsorption spectra of Li4 clusters by the time-dependent density functional theory

作　　者：洪许海 李琼 陈粉荣 赵爽 胡木宏[1] HONG Xuhai;LI Qiong;CHEN Fenrong;ZHAO Shuang;HU Muhong(School of Physics and Electronic Technology,Liaoning Normal University,Dalian 116029,China)

机构地区：[1]辽宁师范大学物理与电子技术学院

出　　处：《辽宁师范大学学报（自然科学版）》2019年第2期168-174,共7页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(11804136;11774344;11774030);辽宁省教育厅科学技术研究青年项目(L201783636)

摘　　要：光吸收谱是识辨团簇异构体的重要工具,常被形象地比作团簇的"指纹".为了研究之前实验中Li4团簇光吸收谱的测量对象,在密度泛函理论框架下,通过构型优化获得5种Li4团簇异构体,优化所得键长与之前理论研究结果符合较好,其中,平面菱形构型的基态能量最为稳定,同时理论预测了四面体构型(C2v)和长方形构型(D2h).基于含时密度泛函理论方法研究了5种Li4团簇异构体的光吸收谱,理论模拟结果表明,平面菱形构型与之前实验测量谱的符合程度最好,为实验的测量对象提供了有力的理论支撑.此外,通过选取2种有代表性的Li4团簇异构体,详细阐述了团簇中原子的空间延展与光吸收谱之间的量子尺寸效应.The photoabsorption spectroscopy are an important tool for identifying cluster isomers,which are often called the fingerprint of clusters vividly.In order to study the measured objects of photoabsorption spectra of Li4 clusters under the previous experiments,five isomers of Li4 clusters have been optimized in the framework of density functional theory.The optimized bond lengths are in good agreement with the results calculated by the previous theoretical works.The ground state energy of planar rhombus configuration is the most stable.The tetrahedron configuration(C2v)and rectangle configuration(D2h)are predicted theoretically.The photoabsorption spectra of five Li4 clusters isomers are studied based on the time-dependent density functional theory.The calculated results manifest that the photoabsorption spectra of planner rhombus isomer agree very well with the experimental spectra,which provides a strongly theoretical support for the measured object in experiments.In addition,the quantum size effect between spacial extensions and the photoabsorption spectra of clusters is stated by combining with two isomers of Li4 clusters.

关 键 词：锂团簇 异构体 几何构型 光吸收谱 含时密度泛函理论 

分 类 号：O561.3[理学—原子与分子物理]