HgmSen (m=1,2,3,n=1,2) 分子和分子离子团簇的结构与光谱性质

Structure and Spectral Properties of HgmSen(m=1,2,3,n=1,2) Molecular and Molecular Ion lusters

摘要:

本工作采用LANL2DZ赝势基组及B3LYP方法对HgmSen(m=1,2,3,n=1,2) 分子和分子离子团簇微观结构和电子性质进行了计算，并用含时密度泛函理论（TD-DFT）计算吸收光谱，得到了基态结构、电子性质、结合能、能隙和偶极矩等微观性质，分析了前线分子轨道特征、指认了全部简谐振动模式、吸收光谱性质。结果表明：当m+n=1~3时，以线型和角型为基态稳定构型，m+n=4~5时，环状为基态稳定构型，且HgSe2团簇分子较其它组成的团簇分子稳定性最强、结合能最大、能隙最小。HgmSen(m=1,2,3,n=1,2) 分子和分子离子团簇都有较好的电子供体和受体等活性部位，导电性良好。不同组成的各团簇的最大吸收波长λmax值呈现的规律性不强，但对于相同组成的团簇分子与其相应正负离子间，出现显著的红移或蓝移现象。本结果可为今后实验及应用研究提供重要理论参考，有助于深入理解实验现象的本质及更好认识大块凝聚物质的某些性质和规律。

Abstract:

This paper adopted the LANL2DZ pseudopotential basis set and B3LYP method to calculate the microstructure and electronic properties of HgmSen(m=1,2,3,n=1,2) molecules and molecular ion clusters. Meanwhile, it utilized the time-dependent density functional theory to calculate the absorption spectra, thus obtaining the ground state structure, electronic properties, binding energy, energy gap, dipole moments and other microscopic properties. Then it analyzed the frontier molecular orbital characteristics, identified all the harmonic vibration mode and absorption spectroscopic properties. The results show that: when m+n=1~3, the linear and angular types are the stable geometry with ground state; when m + n = 4 ~ 5, the ring type is the stable geometry with ground state, besides, compared with other molecular clusters, HgSe2 molecular cluster have the greatest stability, binding energy and the minimal energy gap. HgmSen(m=1,2,3,n=1,2) molecules and molecular ion clusters have better electron donors, receptors and other active sites, that is, great electrical conductivity. The maximum absorption wavelength λmax of each cluster with different composition lacks of regularity, but for the molecular clusters with the same composition and its corresponding positive and negative ions, there appears significant red shift or blue shift. The results could provide theoretical reference for the further experimental and applied research, and it is conducive to studying the nature of experiments as well as certain laws of massive condensed matter.