Structures are grouped into ensembles. An ensemble will contain a set of closely related structures. The most common case is an ensemble containing all conformers of a given species. This is especially powerful, as it allows the user to perform actions on sets of structures. Any calculation that can be launched from a structure can also be launched from an ensemble. Thus, for the user, it is as quick to start a geometry optimization on an ensemble of 10 structures than on a single structure. Moreover, ensembles can be filtered by energetic parameters (cutoff by relative energy or Boltzmann weight) prior to submission. Additionally, it is possible to automatically obtain the Boltzmann-weighted properties computed for each ensemble and each theory level, which reduces further the overhead in dealing with many conformers and model parameters.