碱金属团簇碰撞动力学研究

采用距离相关紧密束缚的分子动力学模型 ,研究了钠原子团簇的碰撞动力学行为 .研究得出 ,对Na6(3D) +Na8系统 ,碰撞参数为b =9a0 时 ,对应于深度非弹性碰撞过程 (DIC) ,在b =13a0 时 ,则对应于准弹性碰撞过程 .另外 ,得到碰撞过程中存在转动 ,其能量大小与碰撞能量Eproj/n以及碰撞参数b均有关系 .随着Eproj/n的增大 ,相对转动减小 ;随着b的变化 ,转动能量先增大后减小 .在b =7a0 时转动最大 ,最大转动能量可达总能量的十分之一 .

Study on the Dynamics of Sodium Cluster Collisions

Within the framework of distance dependent tight-binding molecular dynamics (DDTB-MD), the collision dynamics of sodium cluster Na n has been studied systematically. Some phenomena have been observed at different impact parameters b, such as fusion reaction, deep inelastic collision (DIC) and quasi-elastic collision, which are similar to the nuclear heavy-ion collisions (HIC). For the system of Na 6(3D)+Na 8, the reaction mechanism at b=9a 0 is DIC, but when b is equal to 13a 0, it corresponds to quasi-elastic collision. Furthermore the rotation processes during the collisions, are related to the collision energy and parameter. The larger collision energy is, the earlier relative rotation will occur, and the relaxation time becomes shorter and the relative rotation energy is much smaller. There exists maximal relative rotation energy which corresponding to b=7a 0. When b is smaller than 7a 0, the rotation energy increases with b increasing, otherwise the energy decreases. And the maximal relative rotation energy is corresponding to DIC process. The maximal rotation energy can reach one tenth of total energy, which is much less than that in HIC.