中文摘要：

运用含时密度泛函理论和分子动力学非绝热耦合的方法,研究了水分子在不同脉冲长度的激光场中的电离和动力学行为.计算结果表明,选择适中的激光强度,在同一激光频率的情况下,激光脉冲长度越长,水分子的电离越强;在相同脉冲长度时,激光频率越高,水分子电离越强.此外,当激光频率处于分子共振频率范围内时,长脉冲激光能够增强分子的电离导致分子解离,从而导致电子分布更加集中.当激光频率小于分子共振频率时,长脉冲激光也能够增强分子的电离,从而导致电子分布的变化,但对离子运动的影响很小.

英文摘要：

In the framework of the time-dependent density functional theory（TDDFT） coupled non-adiabatically to molecular dynamics,the ionization and dynamic behaviors of the water molecule in laser fields with the different pulse lengths are investigaed.It is found that when the laser intensity is in the mediate region,the laser field with the longer pulse length can result in the stronger ionizion of the water molecule.With the same pulse length,the higher the laser frequency the stronger the ionization takes place.Furthermore,it is found that when the laser frequency is in the resonant region,the long pulse length can result in the dissociation of the water molecule and the distribution of residual electrons is more concentrated.When the laser frequency is out of the resonant region,although the long pulse length enhances the ionization of the water molecule,it effects less on the dynamics of ions.