Analogously, the search cutoff for the second reaction was slightly increased to 3.1 Å to account for the fact that the reaction between a secondary amine and an epoxide occurred in an already cross-linked, so more crowded, environment. It should be noted that the two search radii were kept constant at all degrees of cure. On the one hand, this was to avoid high-strain configurations involving cross-link bonds between chains too far apart; on the other, short cutoffs also prevent the occurrence of ring spearing (Figure ).