The Modi section is the place where the specified Modus shall be configured. For each possibility refer to the corresponding documentation page:

The Modi section has to contain a section named after the chosen modus and in it the corresponding customization takes place.

Note: In some very rare cases, SMASH will throw an error that an integer overflow would occur constructing the system grid. This happens if the grid at a fixed grid size is constructed with too many cells. One case where this might occur is the List modus, if the input particle list contains particles with nonphysically large position values.