MONSTER aims to optimize and enhance the use of flagship codes under the remit of the Spoke and demonstrate their applicability to the simulation of materials under realistic conditions. MONSTER promotes Italian leadership in computational material science by tackling a crucial problem in the atomistic modelling of materials: how to include the effects of a realistic chemical or mechanical environment in the modelling of the structural and dynamical properties of materials. MONSTER focuses on the effects of a solvent in the growth of nanoparticles or the effects of compression on the plastic deformation of a metal.