非绝热分子动力学的量子路径模拟

发布时间：2019-04-19 03:20

【摘要】：基于近期发展的经典-量子混合模拟非绝热分子动力学的量子路径方案,本文对5个典型势能面模型进行了模拟,包括单交叉模型、双交叉模型、拓展耦合模型、哑铃模型以及双弓模型.由于难以在严格意义上得到退相干速率,数值模拟中,我们比较了三个不同的退相干速率公式,包括冻结高斯波包近似退相干速率、能量分辨速率以及力分辨速率.在模拟过程中,我们恰当地处理了势能面跳跃时的能量守恒和力的反向问题.通过与全量子动力学模拟的精确结果进行对比发现,对于结构较简单的势能面模型,三种退相干速率都能得到较好的结果;然而对于较复杂的势能面模型,由于复杂量子干涉的原因,与其他混合经典-量子动力学方案类似,量子路径方案仍然难以得到较准确的结果.如何发展更加有效的混合经典-量子模拟方案,是未来研究的重要课题.
[Abstract]:Based on the quantum path scheme of classical-quantum hybrid simulation for non-adiabatic molecular dynamics, five typical potential energy surface models, including single-crossover model, double-crossover model, extended coupling model, are simulated in this paper. Dumbbell model and double bow model. Because it is difficult to get the decoherence rate strictly, we compare three different decoherence rate formulas in numerical simulation, including the approximate decoherence rate of frozen Gaussian wave packet, the energy resolution rate and the force resolution rate. In the simulation process, we properly deal with the conservation of energy and the reverse of force when the potential energy surface jumps. Through the comparison with the exact results of the full quantum dynamics simulation, it is found that the three decoherence rates can obtain better results for the potential energy surface model with simple structure. However, for the more complex potential energy surface model, because of the complex quantum interference, similar to other hybrid classical-quantum dynamics schemes, the quantum path scheme is still difficult to obtain more accurate results. How to develop a more effective hybrid classical-quantum simulation scheme is an important research topic in the future.
【作者单位】：天津大学物理系;
【分类号】：O561

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