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才能进行真实的模拟。然而，目前我们还不能用量子力学正确地处理几个原子的动力学。因此，通常人们必须精确地模拟简化模型系统，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用的替代途径是使用量子力学处理系统的一部分，并使用更近似的方法处理系统的一部分。建议的研究旨在开发一种有前途的新的混合动力学算法，其中所有重要的，但理论上困难的，系统的各部分之间的相互作用被严格对待。作为测试的方法，我们建议模拟实验，散射水分子的蛋白质表面。散射过程将使用完整的量子力学来描述，而蛋白质环境将动态和明确地描述，但更近似。结果应该在分子水平上的溶剂化的性质的见解。

Computer simulations have become essential tools to help understand, and even to predict, the results of chemistry experiments. Many fundamental processes require the quantum mecahnical nature of molecules to be taken into account for a realistic simulation. At present, however, we are unable to correctly treat the dynamics of more than a few atoms using quantum mechanics. As a result, typically one has to either simulate a reduced model system exactly, or the full system using approximate methods such as classical molecular dynamics. A useful, alternative, 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 parts of the system is treated rigorously.As a test of the method we propose to simulate experiments that scatter water molecules of 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.