脱附的分子动态特征和几率分布研究

Study on The Molecular Dynamical Character and Probabilite of Desorption

本文根据分子动力学方法,计算了N原子从W(001)表面的脱附过程.结果给出了脱附过程中的几类分子动态特征,以及态—态过程的脱附几率。根据计算结果,考察了各类脱附几率的变化和分布规律。

A. model potential of the interaction of a diatomic moleculer with a solid surface is used to describe 2N+W(001) system. Using this potential, classical trajectory calculations have been carried out to simulate the escape of N atom fromw(001) surface. Mational trajectory show that molecular and different atomic desorption will happen when a N atom adsorbed on w (001) surtacs collide with another. An illustrative picture is provided to study the molecular dynamical character. The probabilities of desorption show that nitrogen from surface into a gas-pnase are mainly intragen atoms, a nitrogen molecule is hardly ever formed. When initial monta is less, the uniatomic desorotion is inportnnt, as the moneta Is more the twiatoniic desorption is essential part. The C.M. moneta, vibrational and rotational state probabilities distributions of the desorbed nitrogen molecules are discussed in trem of the trajectories of molecular desorption. The results show that the C.M. oneta and the rotational state probabilities dislrioutions are non-Boltzmann.The rotational state probabilities distrbutions are different in the ground and the excited states.