Curing cycles were performed using fix bond/react 58 , which executed its own inner loop consisting of three processes (Figure ): reactive-group search, topology change, and structural relaxation. Specifically, bond/react effected accurate topology updates from the pre-to the postreacted configurations (Scheme 5), triggered by a distance cutoff between reacting atoms. These changes were part of an ordinary MD integration step and were followed by a relaxation procedure local to the reaction site. Map files had to be supplied describing the topology of any desired preand post-reaction sites, which were identified in the simulation box by means of a superposition algorithm. Transition from the pre-to the post-reacted configuration involved updating all topological parameters, including partial atomic charges, Lennard-Jones, bond, angle, and dihedral coefficients. After a cross-linking event, all reacting atoms involved were stabilized for 60 fs, by restraining their displacements to a maximum of 0.5 Å per step. To increase the mobility of molecules as much as possible, while still retaining a temperature close to experimental conditions, the curing temperature was set to 503 K 59 (230 °C). Furthermore, to allow the volume of the system to dynamically shrink in response to cross-linking, the reaction was performed in the NPT ensemble, at isotropic atmospheric pressure. Besides the very first curing cycle, which was set to a total duration of 4 ns to exploit the initial high mobility of the reactants, every following curing cycle in the loop was 2 ns long. Furthermore, over the course of curing, both connectivity and coordinate data were dumped every 1 ps, for later analysis and characterization of the system. The If a curing cycle was allowed to proceed until no further reaction took place, curing intensities of about 80% would be achieved, with most of the crosslinking occurring within 4 ns (Figure ).