The mechanism and dynamics of the reaction of C-2(X-1 Sigma(+)(g)) with NH(X-3 Sigma(-)) have been investigated using electronic structure methods. The CASPT2 calculations show that C-2 can add to NH without a barrier. Several intermediates involved in the reaction on the lowest triplet potential energy surface were optimized at the B3LYP level and then the potential energy diagram was refined at more accurate levels of theory. In order to understand the reaction dynamics more quantitatively, direct dynamics calculations have been performed at the B3LYP level. It has been found that the HNC molecule is efficiently produced from the C-2 + NH reaction. (c) 2006 Elsevier B.V. All rights reserved.