  The present work focuses on the characterization of the reaction between
cyanoacetylene and cyano radical by electronic structure calculations of the
stationary points along the minimum energy path. One channel, leading to C4N2
(2-Butynedinitrile) + H, was selected due to the importance of its products.
Using different ab initio methods, a number of stationary points of the
potential energy surface were characterized. The energy values of these minima
were compared in order to weight the computational costs in relation to
chemical accuracy. The results of this works suggests that B2PLYP (and
B2PLYPD3) gave a better description of the saddle point geometry, while B3LYP
works better for minima.
