Quantum molecular dynamics

我们的研究是在广阔的领域计算分子动力学。理论化学面临的巨大挑战之一是研究包含大量原子的系统中的量子动力学，如凝聚态相、簇、纳米结构和生物分子。然而，对于这些多体问题，时间相关Schrödinger方程的完全解是不可行的。因此，为了深入了解这些系统动力学的量子性质，人们必须求助于明智的近似和模型。提出的研究计划包括物理化学系统的量子分子动力学背景下的各个领域，而大型系统的计算方法的发展是我们努力的一个非常重要的重点。计算机模拟在理解物理系统的结构和动力学方面发挥着越来越重要的作用，随着新的方法、算法、理论和模型的发展和完善，这种作用在未来肯定会变得越来越重要。这些以及科学家们可用的计算资源的巨大进步，使人们能够设想在最近的过去似乎难以解决的模拟问题。在这方面，我们计划开发用于研究嵌入超流氦（一种迷人的物质状态）中的分子物种行为所需的模拟方法。在这种类型的环境中，一些分子即使被困在凝聚态中，也会进行自由旋转。其他分子会形成自组装，否则就不会被观察到。为了描述超流体介质本身，对氦的量子动力学的模拟也将是有意义的。我们还参与了半经典方法的开发，这些方法允许使用许多经典分子动力学模拟工具来模拟量子系统的动力学。应用将包括氢键和质子化体系的研究。对于大型系统，如蛋白质配体复合物，我们使用经典模拟，以回答有关相互作用的性质和不同配体的相对亲和力的问题。

Our research is in the broad field computational molecular dynamics. One of the great challenges of theoretical chemistry is the study of quantum dynamics in systems containing a large number of atoms such as condensed phases, clusters, nano-structures and bio-molecules. The full solution of the time-dependent Schrödinger equation is however not feasible for these many-body problems. One therefore has to resort to judicious approximations and models in order to gain insight into the quantum nature of the dynamics of such systems. The proposed research program encompasses various areas within the context of quantum molecular dynamics for systems of interest in physical chemistry and the development of computational methodologies for large systems constitutes a very important focus of our efforts. Computer simulations play an increasingly important role in the understanding of the structure and dynamics of physical systems and this role will certainly gain in importance in the future, as new methods, algorithms, theories and models are developed and refined. These and the tremendous advancements in the computational resources available to scientists now allow one to envisage simulations that seemed intractable in the recent past. In this vein, we plan to develop simulation methods needed for the investigation of the behaviour of molecular species embedded in superfluid helium, a fascinating state of matter. In this type of environment, some molecules undergo free rotation even though they are trapped in a condensed phase. Other molecules will form self-assemblies that are not observed otherwise. The simulation of the quantum dynamics of helium will also be of interest in order to characterize the superfluid medium itself. We are also involved in the development of semi-classical methods that allow the simulation of the dynamics of quantum systems using a lot of the tools of classical molecular dynamics simulations. Applications will include the study of hydrogen-bonded and protonated systems. For large systems such as protein-ligand complexes, we use classical simulations in order to answer questions regarding the nature of the interactions and the relative affinities of different ligands.