| 摘要: | 本研究使用B3LYP/6-311++G(3df)的層級做主要計算，研究鹼土金屬(Be~Ca)吸附在Si11與Si12小型矽團簇上。研究中發現金屬複合團簇顯示Be是最佳的吸附原子，而Mg為最差，因為Mg-Si共價性質沒有Be-Si來的好，而Ca-Si則離子性最強，Be、Mg金屬團簇中HC、MTV呈現相反趨勢而Ca則是變化不大，ΔEg、BE部分則是一致性的變化方向。在過度態的探討中，Si11及Si12各加上一個Be 原子以形成BeSi11、BeSi12 混合團簇，在總自旋態為單重態(singlet)的情況下比較各產物的相對穩定性，結構最佳化則是採用的基底函數 (basis set function)則是較簡單的6-31G* ，計算能量穩定性則採用較精細的6-311++G(3df) 基底以降低基底重疊誤差，研究中發現我們所做的Be@Si12產物比文獻證明兩層非平面六角形所構成的牢籠還來的穩定，並使用(Materials Studio Dmol3) 軟體中三組方法GGA//PBE和GGA//BLYB中的Energy選項證明各個結構穩定性結構，在整體Si11 及Si12過渡態中HC、MTV、HOMO-LUMO gap、結合能BE，顯示Be@ Si12在本研究中各項研究數值都表現最優異。
關鍵字:小型矽團簇、B3LYP、複合團簇、過渡態、牢籠
This study uss B3LYP/6-311++G(3df) as the main method to predict the property of silicon clusters, which is a small cage dasorbed alkaline metals including Be,Mg,Ca .In our research, we found that Be is the best Adsorbate and Mg is the worst one. because of the covalent bonds’ character of Mg-Si is less then Be-Si. And we found that the Ca-Si bond has the greatest ionic property above all. Also, absorbed Be or Mg, the tendency of HC and MTV in the clusters is decreasing, but the cluster which absorbed Calcium does not have any significant change. In the variation of HOMO-LUMOgap and (bindingenergy) is consistency. At the study of transition state, we set the term symbol at singlet state and employed B3LYP6-31G* as our basis set for geometry optimization, and B3LYP 6-311++G*(3df) for energy. Also, we added a Be atom in each Si11 and Si12 clusters to form some new clusters. Hence, we can discus the stabilization of product on the same state. At the energy calculation, heshowed the opposite trend, while Ca is little change in band gaps, (BE) Part is the consistency of the direction of change. Excessive state of Si11 and Si12 each plus a Be atom to form BeSi11,BeSi12 mixed clusters, the total spin states in the singlet state (the singlet) compared the relative stability of the product and the best structure is using the basis functions is a relatively simple 6-31G* calculation of energy to discuss the relative stability using a more sophisticated 6-311G(3df) substrate to reduce substrate overlap error and found lnstitute to do the Be@Si12 cage consisting of two layers of non-planar hexagonal to the product than the documentd stability and use the software (Materials studio Dmol3) method GGA///the PBE and GGA//BLYB Energy options prove various structural stability of the structure overall Si11 and Si12 transition state in the HC, MTV the HOMO-LUMOgap combined with BE show the Be@Si12 in the study the values are the best performing.
Keyword: small Silicon cluster、B3LYP、hybrid clusters、Transition state |
