鹼金族原子吸附在半導體表面已經應用在電子和觸媒工業很幾年了。而本研究所探討的是Al、Ａl2、Al3 與矽氫團簇之表面反應，我們使用的是B3LYP/6-31G*為基組函數之密度波函數的計算方法,藉由其計算的結果探討結構的變化，鍵長、鍵角的改變、是否發生斷鍵
一般而言，我們會由一個基座的矽氫團簇開始計算，再將基座的矽氫團簇數目增加，理論上越大的基底團簇和各種吸附物越能模擬出真實的表面反應，但計算時間也隨之增長。
Adsorption of alkali atom on silicon surface has been applied to microelectronic and catalytical industries for many years. My research is investigate bonding and optimize Al Al2 Al3 adsorb on the Si(111) surface at the B3LYP/6-31G* level. In the case of Si(100), the Si9H12 cluster was used to represent the surface unit with one Si=Si surface dimmer, while in the case of Si(111),different sizes of Si-H clusters were used, depending on the extent of marginal distortion of the clusters. For adsorptions on the Si-H cluster of one surface unit cell, peripheral Si atoms are much free to make unreasonable moving results, we can solve this problem by increasing the number of unit cells. But the more unit cells we use, the more computation time we need.
