Time-dependent Quantum Wave Packet Method In The Application Of The Several System

Molecular reaction dynamics plays an important role in physical chemistry. It’s main work is to solve the Schr?dinger equation. The Schr?dinger equation is one of the most important differential equations in physics and chemistry. It has been used to describe a variety of physical phenomena, such as atoms and molecules scattering problems, resonance decay, and so on. To solve the Schr?dinger equation, people have been proposed many effective methods. Corresponding to Schr?dinger equation of two forms- the time dependent and time independent, there are also two methods which is commonly used is time dependent(TD) method and time independent(TID) method in quantum dynamics. Time dependent method has a lot of advantages.In numerical calculation, time dependent method is more accurate and faster. At the same time it also can provide explicit physical images for the research on dynamics. All calculations in this paper, the time dependent method is used.Discrete variable representation(DVR) has been widely used in the process of simulation reaction scattering. In the iterative calculation, numerical operation is very convenient. We use the sine-DVR method and FE-DVR method to calculate the Na atom reaction probability, and compare the results. We can find that FE-DVR method need less grid pointes and shorter time in the calculation.Time dependent wave packet(TDWP) calculations are carried out to study the initial state for the2 OO ? reaction on the DLLJG potential energy surface(PES). We calculate the total reaction probabilities and integral cross sections(ICSs). Among all the isotope exchange reactions,we choose the endoergic 6+88(R1) and exoergic 8+66(R2) reactions. The total probabilities with J=0 exhibit rapid and sharp oscillations below the threshold energy for the endoergic R1 reaction. On the other hand, there are no such oscillations for the exoergic reaction. We also calculate their ICSs with collision energy below 8 meV. The results in a considerable difference between the ICSs for these two initial states. However, there is not much difference in the ICSs with initial states of0 j =0 and 1 for the endoergic R1 reaction.