Forward-backward Semiclassical Dynamics for Large-scale Simulation

伊利诺伊大学的南希·马克里（Nancy Makri）提交了一份更新提案，旨在开发和应用前向-后向半经典动力学方法来进行多原子系统的大规模模拟。 她建议将这些方法与玻尔兹曼密度的严格路径积分描述，最先进的分子动力学技术相空间的最佳采样，以及力的动态从头计算相结合，以产生一个强大的工具，适用于在数百个粒子的模拟中包括量子力学效应。 还计划扩展到治疗玻色子液体中的交换效应。 应用将集中在液体中的振动弛豫和掺杂氦团簇的动力学。分子振动模式的能量转移在当前感兴趣的许多主题中起着重要作用，例如化学反应途径和激光控制。 很明显，理解大分子、团簇或溶液中能量弛豫现象的机制需要对非线性多体相互作用和量子效应进行精细处理，这将在本研究中进行。

Nancy Makri at University of Illinois has submitted a renewal proposal to develop and apply forward-backward semiclassical dynamics methods for large-scale simulations of polyatomic systems. She proposes to integrate these methods with a rigorous path integral description of the Boltzmann density, state-of-the-art molecular dynamics techniques for optimal sampling of phase space, and on-the-fly ab initio calculations of forces to produce a powerful tool suitable for including quantum mechanical effects in simulations with hundreds of particles. Extension to treat exchange effects in bosonic fluids is also planned. Applications will focus on vibrational relaxation in liquids and the dynamics of doped helium clusters.Energy transfer in and out of molecular vibrational modes plays an important role in many topics of current interest, such as chemical reaction pathways and laser control. It is clear that understanding the mechanism of energy relaxation phenomena in large molecules, clusters, or in solution requires a delicate treatment of nonlinear many-body interactions and quantum effects, which will be pursued in this research effort.