Nhat Pham Vu, Trang Nguyen Thi Bao, Dang Minh Triet, Thanh Si Nguyen, Thao Tran Thi Ngoc, Thao Pham Thi Bich, Nguyen Minh Tho
Molecule and Materials Modeling Laboratory, Department of Chemistry, Can Tho University, Can Tho 90000, Vietnam.
School of Education, Can Tho University, Can Tho 90000, Vietnam.
ACS Omega. 2024 Sep 8;9(37):38467-38476. doi: 10.1021/acsomega.4c02724. eCollection 2024 Sep 17.
Density functional theory (DFT) calculations are carried out to determine the geometries and electronic and nonlinear optical (NLO) properties of the doubly doped gold clusters in three charge states M @ Au with M = W, Mo and = 0, ±1. At their lowest-lying equilibrium structures, the impurities that are vertically encapsulated inside a cylindrical gold framework, significantly enhance the stability and modify properties of the host. The presence of M units results in the formation of a tube-like ground state, which is identified for the first time for gold clusters. Having 30 itinerant electrons, the electron shell of M@Au can be described as 1S1P1D2S{1F 1F }1F {1F 1F }{1F ,1F }. The species is thus stabilized upon doping, but it is not a magic cluster. The optical transitions are shifted to the lower-energy region upon doping Mo and W atoms into Au . The static and dynamic NLO properties of M@Au are also computed and compared to those of the pure Au (having the same number of atoms) and an external reference molecule, i.e., para-nitroaniline (-NA). For hyperpolarizabilities, the doped clusters possess smaller values than those of their pure counterparts but much larger values than the -NA. Of the doubly doped systems, the neutral M@Au exhibits particularly high first and second hyperpolarizability tensors. The doped cluster units can also be used as building blocks for the design of gold-based nanowires with outstanding electronic and optical characteristics.
进行密度泛函理论（DFT）计算，以确定处于三种电荷态M@Au（M = W、Mo且 = 0、±1）的双掺杂金团簇的几何结构、电子性质和非线性光学（NLO）性质。在其最低能量的平衡结构中，垂直封装在圆柱形金框架内的杂质显著增强了主体的稳定性并改变了其性质。M单元的存在导致形成一种管状基态，这是首次在金团簇中被识别出来。M@Au拥有30个巡游电子，其电子壳层可描述为1S1P1D2S{1F 1F }1F {1F 1F }{1F,1F }。因此，该物种在掺杂后得以稳定，但它不是一个幻数团簇。将Mo和W原子掺杂到Au 中后，光学跃迁向低能量区域移动。还计算了M@Au的静态和动态NLO性质，并将其与纯Au （具有相同原子数）和外部参考分子对硝基苯胺（-NA）的性质进行了比较。对于超极化率，掺杂团簇的值比其纯对应物小，但比-NA大得多。在双掺杂体系中，中性的M@Au表现出特别高的第一和第二超极化率张量。掺杂的团簇单元还可作为构建具有优异电子和光学特性的金基纳米线的基本单元。
