Novel Algorithms for Many-Body Classical Dynamics and Global Optimization

约翰·斯特劳布（John Straub）获得了理论与计算化学项目的资助，致力于开发用于执行多体经典动力学和全局能量优化的新算法。他将经典分子动力学问题重新定义为一个Liouville算子，该算子作用于由高斯波包的Hartree积表示的时变相空间分布。结果是一组简单的一阶运动方程，用于在一定温度或能量下分布的近似时间依赖性。这种方法将应用于表面上原子或分子动力学的研究，分子流体和生物分子的模拟，以及增强的自由能摄动计算。在第二个但相关的研究领域中，Straub将开发一种方法，通过虚时间薛定谔方程的近似解在势能表面上找到全局能量最小值。计算机模拟提供了许多分子水平的见解，以了解发生在溶液和表面上的化学过程。这项技术非常强大，但受到与当前超级计算机的速度和执行此类模拟的可用时间相关的统计抽样问题的限制。斯特劳布正在开发一种执行分子模拟的新算法，这应该是统计抽样的重大改进。如果成功，这种新算法可以显著减少在分子模拟中获得有意义的采样统计所需的计算资源。* * *

9306375 Straub John Straub is funded by a grant from the Theoretical and Computational Chemistry Program to develop new algorithms for performing many-body classical dynamics and global energy optimization. He has recast the classical molecular dynamics problem into a Liouville operator which operates on a time dependent phase space distribution represented by a Hartree product of Gaussian wave packets. The result is a set of simple first order equations of motion for the approximate time-dependence of the distribution at contant temperature or energy. This methodology will be applied to studies of the dynamics of atoms or molecules on surfaces, the simulation of molecular fluids and biomolecules, and enhanced free energy perturbation calculations. In a second but related area of study, Straub will develop a method for finding the global energy minimum on a potential energy surface through an approximate solution to the Schrodinger equation in imaginary time. %%% Computer simulations have provided a number of molecular level insights into chemical processes which occur in solution and on surfaces. The technique is very powerful, but is limited by statistical sampling problems associated with the speed of current supercomputers and the time available to perform such simulations. Straub is developing a new algorithm for performing molecular simulations which should be a major improvement in statistical sampling. If successful, this new algorithm could provide a significant decrease in the amount of computational resources required to obtain meaningful sampling statistics in molecular simulations. ***