  The numerical simulation of granular systems of even moderate size is a
challenging computational problem. In most investigations, either Molecular
Dynamics or Event-driven Molecular Dynamics is applied. Here we show that in
certain cases, mainly (but not exclusively) for static granular packings, the
Bottom-to-top Reconstruction method allows for the efficient simulation of very
large systems. We apply the method to heap formation, granular flow in a
rotating cylinder and to structure formation in nano-powders. We also present
an efficient implementation of the algorithm in C++, including a benchmark.
