Wavepacket dynamics for the future: A general purpose HPC-compliant program.

波包动力学模拟直接解决了与时间相关的薛定谔方程，并提供了一个分子系统，可以很容易地与高精度实验，如激光光谱学和分子束散射的可视化描述。然而，它们是需要大量计算机资源的计算，并且通常只能处理几个（3-4个）原子。可以处理较大系统动力学的各种近似解确实存在，但通常以丢失潜在的关键量子信息为代价。一个特别强大的算法，能够处理超过4个原子，但收敛于准确的结果是MCTDH方法。海德堡MCTDH软件包包括该算法的编码，该算法已经在化学物理的各个领域提供了许多基准计算，特别是光化学。通过利用现代计算机体系结构，我们将能够访问更大的系统，从而推动计算化学的边界。计算机集群，其中一些多处理器板连接在一起，正在成为科学界的普遍。然而，计算机程序需要以特殊的方式编写，以利用这些机器的架构。特别是，程序的资源密集型部分需要并行化。这意味着算法的不同部分可以同时在不同的处理器上单独处理。然而，MCTDH程序是一个串行程序，一个接一个地执行命令，需要进行更改以最佳地使用机器。拟议的工作是更新代码以处理其缺陷。不仅将MCTDH算法并行化以提高其效率，还将在程序中实现其他方法以生成更通用的代码。最终的结果将是一个程序，可以使用的非专业人士，并可以在该领域的未来发展的方式，电子结构程序，如高斯和Molpro可以增长。这将推动量子动力学向前发展，以便在未来可以处理更大的系统，包括蛋白质内部和溶液中的反应。这些问题目前远远超出了现有任何量子动力学程序的能力，因此这将代表化学反应研究的一个步骤变化。

Wavepacket dynamics simulations solve the time-dependent Schroedinger equation directly and provide a visual description of a molecular system that can be easily related to high precision experiments such as laser spectroscopy and molecular beam scattering. They are, however, calculations that need large computer resources and are usually able to treat only a few (3-4) atoms. Various approximate solutions that can treat the dynamics of larger systems do exist, but usually at the cost of losing potentially crucial quantum information. A particularly powerful algorithm able to treat more than 4 atoms, yet converge on the exact result is the MCTDH method. The Heidelberg MCTDH package includes a coding of this algorithm that has already provided a number of benchmark calculations in various fields of chemical physics, particularly photochemistry. By exploiting modern computer architecture we will be able to access even larger systems, and thus push back the boundaries of computational chemistry.Computer clusters in which a number of multi-processor boards are connected together are becoming widespread in the scientific community. A computer program, however, needs to be written in a special way to take advantage of the architecture of these machines. In particular, resource-intensive parts of the program need to be parallelised . This means that different parts of the algorithm can be treated separately on different processors at the same time. The MCTDH program, however, is a serial program, executing commands one after another, and changes will need to be made to use the machines optimally. The proposed work is to update the code to treat its deficiencies. Not only will the MCTDH algorithm be parallelised to improve its efficiency, but also other methods will be implemented into the program to generate a more general code. The end result will be a program that can be used by non-specialists and that can grow with future developments in the field, in the waythat electronic structure programs such as Gaussian and Molpro can. This will move quantum dynamics forwards so that in the future much larger systems can be treated, including reactions inside proteins and in solution. These are problems which are currently well beyond the capabilities of any quantum dynamics program in existence and this would therefore represent a step change in the study of chemical reactions.