Collaborative large scale MD simulation code that is inherited from the originally developed SPaSM (Scalable Parallel Short-range Molecular dynamics) code in Los Alamos National Lab. (only internal). With the trillion atom simulation it should honor the father of the SPaSM code [1] [2], Peter S. Lomdahl, who together with his student Dave Beazley first initiated and spearheaded SPaSM in the early 1990s, at that time the SPaSM code was successfully used to simulate millions of atoms addressing impact and crack propagation phenomena in solids.

[1] D. M. Beazley and P. S. Lomdahl, Parallel Computing 20, 173 (1994)

[2] D. M. Beazley and P. S. Lomdahl, Comput. Phys. 11, 230 (1997).

In our later development with guidance of Dr. Germann, we have accomplished more functionalities into the original SPaSM code, e.g. various mechanical loading mode via equilibrium MS/MD scheme, an automatic atomistic analysis and visulization kit for large scale simulation including crystal defects and crystallite orientation, and a built-in atomistic modelling for nanostructured polycrystals and nanocomposites. Nevertheless, we would like to inherit the abbreviation "SPaSM Simulator" for historical and respectful reasons. Note that the largest shock wave simulation was performed by original SPaSM code in 2008 at Los Alamos National lab. trillion (10^12) atoms by Tim C. Germann.