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arXiv 0710.4229cond-mat.mtrl-sci
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金属和绝缘体的鲁棒非绝热分子动力学

Robust non-adiabatic molecular dynamics for metals and insulators

L. Stella, M. Meister, A. J. Fisher, A. P. Horsfield

摘要:

我们提出了一个新的配方的相关电子-离子动力学(CEID)计划,系统地改善Eklfest动力学包括量子涨落周围的平均场原子轨迹。我们表明,该方法可以模拟模型的非绝热电子跃迁,并测试它对含时薛定谔方程的精确积分。与以前的CEID公式不同,该方案的准确性取决于一个可调参数,该参数设置了包含的原子波动水平。对一个模型二能级系统,证明了通过增加可调参数,可以收敛到精确的动力学。该算法提供了一个光滑的非绝热电子跃迁的描述,满足运动学约束(能量和动量守恒),并保持量子相干性。该算法的适用性更复杂的原子系统进行了讨论。

英文摘要:

We present a new formulation of the correlated electron-ion dynamics (CEID) scheme, which systematically improves Ehrenfest dynamics by including quantum fluctuations around the mean-field atomic trajectories. We show that the method can simulate models of non-adiabatic electronic transitions, and test it against exact integration of the time-dependent Schroedinger equation. Unlike previous formulations of CEID, the accuracy of this scheme depends on a single tunable parameter which sets the level of atomic fluctuations included. The convergence to the exact dynamics by increasing the tunable parameter is demonstrated for a model two level system. This algorithm provides a smooth description of the non-adiabatic electronic transitions which satisfies the kinematic constraints (energy and momentum conservation) and preserves quantum coherence. The applicability of this algorithm to more complex atomic systems is discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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