In this letter, we investigate the reaction paths for the N2 dissociation on the Ru(112¯1) surface. Our results show that the N 2 molecule has two preactivated states where it is in a 4-fold coordination. The reaction path which involves the N2 in a B5 coordination in the transition state has an apparent activation energy of 19 kJ/mol. This is about 16 kJ/mol lower than the path in which N2 has a B4 coordination. Our results confirm that it is a B5 coordination of the N2 in the transition state that leads to a low dissociation barrier and that such a coordination may be found on stepped, double stepped, and open surfaces as well as nanoparticles. © 2008 American Chemical Society.