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对铝原子簇Al_n(n=1～10,12,13)已报导过的理论预测几何构型进行合理选择,用量子化学CNDO/2法研究了单分子一氧化碳在这些簇上取不同吸附位形时的吸附作用。结果表明吸附强度随簇尺度的变化呈“幻数”特性:Al_2、Al_6、Al_(12)簇具有特别高的吸附能,与实验观测结果相符。采用作者建议的推广电子壳模型可合理解释这一尺度效应。对Al_(12)和Al_(13)簇电子结构的分析进一步支持了壳模型的观点。随着簇的增大,尺度效应逐步减弱并趋向于体相铝的性质。
The theoretical prediction geometric configurations reported for aluminum cluster Al_n (n = 1 ~ 10, 12, 13) have been studied. Quantum chemical CNDO / 2 method has been used to study the adsorption states of single molecular carbon monoxide on these clusters When the adsorption. The results show that the adsorption strength exhibits a “magic number” with the change of the cluster size. The Al 2, Al 6 and Al 12 clusters have a very high adsorption energy, which is consistent with the experimental observations. The scale-up effect can be reasonably explained using the proposed popularization shell model. The analysis of the electronic structures of Al 12 and Al 13 clusters further supports the view of the shell model. As the cluster increases, the scale effect gradually weakened and tends to the nature of bulk aluminum.