Supramolecular aggregates of synthetic dye molecules offer great perspectives to prepare biomimetic functional materials for light-harvesting and energy transport. The design is complicated by the fact that structure-property relationships are hard to establish, because the molecular packing results from a delicate balance of interactions and the excitonic properties that dictate the optics and excited state dynamics, in turn sensitively depend on this packing. Here we show how an iterative multiscale approach combining molecular dynamics and quantum mechanical exciton modeling can be used to obtain accurate insight into the packing of thousands of cyanine dye molecules in a complex double-walled tubular aggregate in close interaction with its solvent environment. Our approach allows us not only to answer open questions on the structure of these prototypical aggregates, but also about their molecular-scale structural and energetic heterogeneity, and the microscopic origin of their photophysical properties. This opens the route to accurate predictions of energy transport and other functional properties.

合成染料分子的超分子聚集体为制备仿生功能材料以进行光收集和能量传输提供了广阔的前景。由于分子堆积是由相互作用的微妙平衡和决定光学和激发态动力学的激子性质（进而敏感地依赖于这种堆积）产生的，因此结构与属性之间的关系很难建立，从而使设计变得复杂。在这里，我们展示了如何使用分子动力学和量子力学激子建模相结合的迭代多尺度方法来获得对复杂双壁管状聚集体中数千种花菁染料分子与溶剂环境紧密相互作用的堆积的准确了解。我们的方法不仅使我们能够回答关于这些原型聚集体结构的公开问题，而且还可以回答有关它们的分子尺度结构和高能异质性以及其光物理性质的微观起源。这为准确预测能量传输和其他功能特性开辟了道路。