Na5, Na6和Na7团簇光学吸收谱的理论研究

以含时密度泛函理论为基础，结合从头赝势方法运用含时局域密度近似计算了Na₅，Na₆和Na₇团簇的动力学极化强度，并通过傅里叶变换得出了团簇的光学吸收谱.研究表明，计算结果可以较好地再现实验谱，而且Na₆和Na₇团簇的结果和组态相互作用的结果符合较好.二维结构和三维结构的Na₆团簇的计算结果表明，只有二维结构可出现低于2 eV以下的峰，而且二维结构光谱的计算结果与实验结果符合较好. 关键词： 光吸收谱 Na团簇 含时局域密度近似

Optical absorption spectra of Na5, Na6 and Na7 clusters: a theoretical study

In the frame of time-dependent density functional theory, the dynamical polarizabilities of Na₅, Na₆ and Na₇ clusters are calculated using a time-dependent local density approximation. By using Fourier transformation, the optical absorption spectra of Na₅, Na₆ and Na₇ clusters are obtained from their dynamical polarizabilities. It is shown that experimentally measured optical absorption spectra of Na₅, Na₆ and Na₇ clusters are reproduced in our calculations. Furthermore, the calculations of Na₆ and Na₇ clusters are in good agreement with the results of configuration interaction method. Compared with the three-dimensional structure of Na₆, the calculated optical absorption spectra of Na₆ with the two-dimensional structure are more close to the experimental data.