Milano Chemistry Molecular Simulation (MiCMoS): a versatile tool to study molecular systems in condensed phase

The Milano Chemistry Molecular Simulation (MiCMoS) platform is a powerful computational tool to study molecular systems in condensed phase. The software offers a wide range of capabilities and is freely available to the scientific community, together with step-by-step tutorials. MiCMoS can compute lattice energies and analyze crystal packing in a static fashion, using both Gavezzotti’s PIXEL approach and an atom-atom force field-based formalism . Most importantly, the program can account for dynamic effects in crystals, pure liquids, homogeneous and heterogeneous solutions, and non-periodic nanostructures. To this end, it is provided with Molecular Dynamics (MD) and Monte Carlo (MC) modules that rely on accurately calibrated classical force fields. Moreover, the software offers extensive temperature and pressure control capabilities, to perform studies in various thermodynamic conditions. A notable feature of MiCMoS is a novel algorithm for biasing kinetic energy, which promotes the aggregation of molecules in the liquid phase and prevents aggregates from being destroyed by thermal motion. A more recent upgrade consists in the possibility of simulating confined systems, namely nanolayers, nanotubes and nanocavities. The underlying idea is to use classical MD methods to investigate early aggregation phenomena on the path toward nucleation, providing the atomistic detail that is not otherwise amenable to experimental determination. Recently, MiCMoS was successfully employed to gain insights into various crystallographic problems, including stability of nanocrystals, reorientation phenomena in organic plastic phases, phase transitions under anisotropic compression regimes, and behavior of undercooled liquids in confined nanocavities. An overview of the main achievements will be given.