定向电场下W_(6)C_(6)团簇的超卤素调制及非线性光学特性  

Hyperhalogen modulation and nonlinear optical properties of W_(6)C_(6) clusters under a directed electric field

作　　者：蔡璧钧 段宇静 魏强 CAI Bi-Jun;DUAN Yu-Jing;WEI Qiang(School of Science,Chongqing University of Technology,Chongqing 400050,China)

机构地区：[1]重庆理工大学理学院,重庆400050

出　　处：《原子与分子物理学报》2025年第3期72-76,共5页Journal of Atomic and Molecular Physics

基　　金：重庆市研究生科研创新项目(CYS20344);重庆理工大学研究生高质量发展项目(gzlcx20232092)。

摘　　要：本文采用密度泛函(DFT)方法研究了定向外电场(OEEF)对W_(6)C_(6)团簇几何结构、电子性质以及非线性光学响应(NLO)的影响.计算结果表明W_(6)C_(6)的结构在一定OEEF强度下可以保持稳定.OEEF可以增大W_(6)C_(6)团簇的电子亲和能(EA值),且在特定强度下,OEEF可以将W_(6)C_(6)团簇转变为超卤素.通过对EA值的非线性拟合可以实现对W_(6)C_(6)团簇的连续调制.进一步对不同外电场下W_(6)C_(6)团簇的最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)能级进行分析,发现OEEF降低了W_(6)C_(6)团簇LUMO能级是其EA值增大的主因.此外,OEEF可以显著增大W_(6)C_(6)团簇的平均极化率和第一超极化率,尤其是第一超极化率,改变其非线性光学性质.The effects of an oriented external electric field(OEEF)on the geometric structure,electronic properties and nonlinear optical response(NLO)of W_(6)C_(6) clusters were investigated by using density functional theory(DFT).The results show that the structure of W_(6)C_(6) is stable at a certain OEEF strength.OEEF can increase the electron affinity of W_(6)C_(6) cluster(EA value)and convert W_(6)C_(6) cluster into hyperhalogen at a specific strength.The continuous modulation of W_(6)C_(6) clusters can be realized by nonlinear fitting of EA values.Furthermore,the higbest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO)energy levels of W_(6)C_(6) clusters under different external electric fields were analyzed,it is found that the decrease of LUMO energy level by OEEF is the main reason for the increase of EA value of W_(6)C_(6) clusters.In addition,OEEF can significantly increase the average polarizability and the first hyperpolarizability,especially the first hyperpolarizability,of W_(6)C_(6) clusters,and change their nonlinear optical properties.

关 键 词：定向外电场 超原子 密度泛函理论 NLO W_(6)C_(6)团簇 

分 类 号：TB34[一般工业技术—材料科学与工程]