本研究是針對小的金屬分子Si(111)表面的吸附。目前先以簡單矽氫原子團簇代表還未重建的Si(111)理想表面,模擬Na、Na2、Na3的吸附，使用的軟體是GAUSSIAN03，用B3LYP/6-31G*計算方法來進行各種吸附方向的結構最佳化。我們先由代表一個表面單位晶格的矽氫原子團簇開始，後來增加至四個unit cells，原因是矽氫原子團簇太小時最佳化下來，週邊的矽原子因為較自由，所以會發生不合理的位移。當矽氫原子團簇加大時，這樣的情形可以逐漸獲得改善，原則上能讓我們把越大的金屬團簇和含氧的化合物放在愈大的矽氫原子團簇的中間，就愈接近真實的表面狀況，但計算時間也大量增加。鹼金族雙原子及三原子分子吸附在矽表面之後，其鍵結軌域的電子注入表面的dangling bonds，則造成Na和Na之間的鍵結斷裂。
We investigated bonding and optimized geometries of Na、Na2 and Na3 adsorbed on the Si(111) surfaces at the B3LYP/6-31G* level. 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. Finally, we put O2 onto the neighbor site of sodium adsorbate to see how oxygen interacts with metal and surfaces. This is expected to understand the oxidization process in the semiconductor industry. General speaking, the bond lengths in Na2 and Na3 adsorbates are greatly reduced due to the flowing of charge density from metal antibonding orbitals into the surface dangling bonds.
