CCP6 Renewal: Developing Quantum Dynamics for Large Systems

计算机模拟已经成为帮助理解甚至预测化学实验结果的重要工具。许多基本过程需要考虑分子的量子力学性质来进行真实的模拟。然而，目前我们还不能用量子力学正确地处理少数原子的动力学。因此，人们必须精确地模拟一个简化模型系统，或者使用近似方法（如经典分子动力学）模拟整个系统。克服这些限制的一个有效途径是用量子力学处理系统的一部分，用更近似的方法处理系统的一部分。提出的研究旨在开发一种有前途的新混合动力学算法，其中所有重要的，但理论上困难的，系统不同部分之间的相互作用被严格处理。作为对该方法的测试，我们建议模拟将水分子从蛋白质表面散射出去的实验。散射过程将使用全量子力学来描述，而蛋白质环境将被动态和明确地描述，但更近似。结果应该在分子水平上提供对溶剂化性质的见解。

Computer simulations have become essential tools to help understand, and even to predict, the results of chemistry experiments. Many fundamental processes require the quantum mechanical nature of molecules to be taken into account for a realistic simulation. At present, however, we are unable to treat correctly the dynamics of more than a few atoms using quantum mechanics. As a result, one has to simulate either a reduced model system exactly, or the full system using approximate methods such as classical molecular dynamics. A useful route to overcome the limitations is to treat part of a system using quantum mechanics, and part of the system using more approximate methods. The proposed research aims to develop a promising new mixed dynamics algorithm in which the all important, but theoretically difficult, interaction between the different parts of the system is treated rigorously.As a test of the method we propose to simulate experiments that scatter water molecules off the surface of a protein. The scattering process will be described using full quantum mechanics, while the protein environment will be described dynamically and explicitely, but more approximately. Results should give insights into the nature of solvation at the molecular level.