Development of full dimensional ab-initio direct dynamics method and its application to chemical reactions

发展了一种直接从头算动力学方法，用于研究离子和原子在石墨表面的几个化学反应和扩散动力学。在这种新方法中，反应体系的所有自由度都被精确地包含在反应过程中。作为模型，用直接从头算动力学方法研究了水原子团簇的电离动力学。研究发现，电离后的水分子中的一个质子在电离后的200 ms内迅速转移到相邻的水分子中。通过轨道计算，研究了水分子团簇的电子俘获。超额电子首先被捕获在水团簇的表面态，然后水分子逐渐向超额电子方向移动。电子的1s-2p跃迁随溶剂化时间发生蓝移。

Direct ab-initio dynamics method to treat reaction dynamios has been developed and applied to several chemical reactions and diffusion dynamics of ion and atoms on graphite surfaces. In this new method, all degrees of freedom of reaction system are precisely included during tbe reaction. As a model case, the ionization dynamics of water clusters have been investigated by means of direct ab-initio dynamics method. It was found that a proton of the ionized water molecule is rapidly transferred to the neighboring water molecule within 200 fs after the ionization. Electron capture of water clusters was also studied by the trajectory calculations. The excess electron was trapped firstly in the surface state of water cluster, and then the water molecules oriented gradually toward the excess electron. The 1s-2p transition of electron was blue-shifted as a function of solvation time.