In principle, the number of chromophores considered in EXASH is limited only by the computational resources: if another chromophore is added to the system, one has mainly to add the related QM/MM calculation (at each integration time step). The price is that only states that can be written as linear combinations of local excitations can be considered. The first application of EXASH consisted of the simulation of the dynamics of an azobenzene dimer held together by sulfur bridges. EXASH revealed that although fast, the excitation transfer between chromophores is limited to the * manifold and absent for n* states.