NER: Scalable techniques for massively parallel nanomaterial simulations for long-time behavior

该提案是响应纳米尺度科学与工程计划NSF 03-043， NER类别而收到的。研究人员解决了一类涉及碳纳米管组装的问题，其中界面起着关键作用。这类问题属于长时间尺度的模拟，经典的过渡态理论在其中不适用。解决方案策略是基于利用大规模并行性的力量。通过空间分解的传统并行化将不有效，因为那会导致细粒度。提出的工作旨在使用预测-验证方法实现时间并行化。研究的关键问题之一是开发合适的预测因子。这一努力的成功结果可以与多尺度模拟相结合，可以预测比今天大几个数量级的时间尺度的材料特性。上述研究成果在纳米涂层、纳米传感器、纳米电子学和纳米复合材料等领域均有应用。在纳米技术发展的当前阶段，由于尺寸效应，与实验相比，计算（理论、建模和模拟）起着主导作用。广泛应用计算模拟的障碍之一是难以获得真实的时间尺度。本研究解决了这一关键问题。上面提到的具体应用只是纳米技术目前设想的一些应用，纳米级界面的研究将直接适用于这些应用。对物理和计算的一些基本理解有可能用于更广泛的应用，包括纳米生物技术。

This proposal was received in response to Nanoscale science and engineering initiative NSF 03-043, category NER. The investigators address a class of problems involving an assembly of carbon nanotubes, wherein interfaces play a key role. This class of problems pertains to long time scale simulations in which classical transition state theories are not applicable. The solution strategy is based on harnessing the power of massive parallelism. Conventional parallelization through spatial decomposition will not be effective since that will lead to fine granularity. The proposed effort is aimed at time-parallelization using a predictor-verifier approach. One of the key research issues is to develop appropriate predictors. Successful results from this endeavor can be integrated with multi-scale simulations that can predict material properties to time scales several orders of magnitude greater than that today.The above research effort has applications in the areas of nanocoatings, nanosensors, nanoelectronics and nanocomposites. In the current stage of the development of nanotechnology, computation (theory, modeling and simulations) is playing a leading role, compared to experiments, because of size effects. One of the stumbling blocks to the widespread use of computational simulations is the difficulty in achieving realistic time scales. This research addresses this key issue. The specific applications mentioned above are but a few of the currently envisioned applications of nanotechnology for which this research on nanoscale interfaces will be directly applicable. Some of the fundamental understanding of both physics and computations has potential use for a wider class of applications, including nano-biotechnology.