INTERACTION ENERGIES ASSOCIATED WITH SHORT INTERMOLECULAR CONTACTS OF C-H BONDS - STRUCTURE AND ENERGETICS OF THE INTERACTION BETWEEN CH4 AND CN-

On the basis of SCF and single reference MP2 calculations, the full potential energy surface of the interaction between CH4 and CN- was studied using extended basis sets of up to near Hartree-Fock limit quality. Collinear arrangements C-N-...H-CH3 and N-C-...H-CH3 are found to be the only two energy minima. The binding energies of these two structures are calculated to be 2.5 and 2.1 kcal/mol, respectively, at the MP2 level. The full vibrational analyses of the two structures show a red-shift of about 30 cm-1 for the nu-s C-H stretching.