Be_2二聚体分子形貌的理论研究

The theory study on molecular face of Be_2 dimer

应用MP2、HF和B3LYP/6-311++G(3df,3pd),得到了Be2二聚体在单重态和三重态下的能量与核间距、电离能与核间距的关系曲线,并分析了这3种方法对其能量、电离能变化的影响;结合分子形貌理论详细介绍了单重态下,在核间距变化的过程中电子密度的变化趋势,形象地展示了由小的核间距到平衡位置再到较远的距离,即2个Be原子完全分开形成孤立原子的过程中,边界轮廓的大小和形状随着核间距变化的动态过程.这里使用MP2/6-311++G(3df,3pd)计算了第一电离能的变化趋势.使用MELD精密从头计算中的CISD/6-311++G(3df,3pd)方法,并结合我们自编的分子形貌程序,描绘出了Be2的分子内禀特征轮廓即分子形貌并计算了Be2的内禀特征参数,得到了很好的结果.

In this paper,the relations curves of Be2 dimer energy and nuclear distance,the ionization energy and nuclear distance were obtained by MP2,HF and B3LYP/6-311＋＋G（3df,3pd） under the singlet and triplet states,the changes of energy and the ionization energy of Be2 were analyzed by the three methods.Moreover,the changing trend of the electron density with the change of nuclear distance under the singlet state was analyzed in detail by the combination of the over three methods and Molecular Face Theory.The Molecular Face Theory vividly revealed the change process of the size and shape of the boundary contour with the change process of nuclear distance which were from the small distance to the balance distance and then to the distance of two Be atoms completely separate.The change trend of the first ionization energy with different nuclear separate was obtained in MP2/6-311＋＋G（3df,3pd）.The Molecular Intrinsic Characteristic Contour of the Be2,i.e.Molecular Face was described through the combination of the CISD/6-3 11＋＋g（3df,3pd） of the exact ab initio MELD and the Molecular Face Theory which was compiled by ourselves,also the Be2 intrinsic parameters were better obtained,which were very good.