Tan Li-Ping, Die Dong, Zheng Ben-Xia
School of Science, Xihua University, Chengdu 610039, China.
School of Science, Xihua University, Chengdu 610039, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Feb 15;267(Pt 2):120545. doi: 10.1016/j.saa.2021.120545. Epub 2021 Oct 27.
Density functional theory (DFT) and particle swarm optimization (PSO) have been applied to study the growth behavior, electronic properties and spectra of neutral, anionic and cationic aluminum clusters with 3-20 atoms. Many isomers have been obtained through a comprehensive structural search. The results indicate that the ground state structures of neutral and anionic aluminum clusters follow an identical periodic growth law. When the number of atoms is 6-11 and 13-18, Al atoms in these clusters grow around an octahedral cluster nucleus and an icosahedral cluster nucleus, respectively. For Al (n ≤ 14 and n ≠ 7) clusters, the most stable structure is different from that of Al or Alclusters. When n > 14, the ground state structure of Al clusters is similar to that of Al or Alclusters. The electronic properties of aluminum clusters have been analyzed by the averaged binding energy, second-order difference of energy, energy gap and dissociation energy. It is found that the Al and Al clusters have very high stability and a large energy gap and can be regarded as two superatoms. The aluminum cluster with 18 or 40 valence electrons are the least likely to lose an electron. The dissociation behavior of Al clusters caused by collision is reasonably explained by means of the dissociation energy. The optical absorption spectra of neutral aluminum clusters have been simulated by using the time-dependent density functional theory. The ground states of anionic aluminum clusters have been determined by comparing theoretical photoelectron spectra (PES) with experimental findings. Infrared and Raman spectra of cationic aluminum clusters have been forecasted and can assist in identifying the most stable structure in future experiments.
密度泛函理论（DFT）和粒子群优化算法（PSO）已被用于研究含3 - 20个原子的中性、阴离子和阳离子铝团簇的生长行为、电子性质和光谱。通过全面的结构搜索获得了许多异构体。结果表明，中性和阴离子铝团簇的基态结构遵循相同的周期性生长规律。当原子数为6 - 11和13 - 18时，这些团簇中的铝原子分别围绕八面体团簇核和二十面体团簇核生长。对于Al（n≤14且n≠7）团簇，最稳定的结构与Al或Al团簇的不同。当n>14时，Al团簇的基态结构与Al或Al团簇的相似。通过平均结合能、能量二阶差分、能隙和解离能对铝团簇的电子性质进行了分析。发现Al和Al团簇具有非常高的稳定性和大的能隙，可被视为两个超原子。具有18个或40个价电子的铝团簇最不容易失去电子。利用解离能合理地解释了碰撞引起的Al团簇的解离行为。采用含时密度泛函理论模拟了中性铝团簇的光吸收光谱。通过比较理论光电子能谱（PES）与实验结果确定了阴离子铝团簇的基态。预测了阳离子铝团簇的红外和拉曼光谱，可为未来实验中识别最稳定结构提供帮助。
