Reply to the 'Comment on "dynamic factors in the reactions between the magic cluster Al ₁₃ ^- and HCl/HI": A wavefunction instability problem.' by Young-Kyu Han, Phys. Chem. Chem. Phys. 2012, DOI: 10.1039/C2CP23908F

The reaction between a metal cluster Al13 ^- and an inorganic molecule HI involves charge transfer and density functional calculations has deficiency to estimate the activation barrier due to the self-interaction error. Coupled-cluster calculation with single and double excitation (CCSD) based on spin-unrestricted Hartree-Fock wavefunction can improve the calculated barrier and the choice of basis set is important for the calculation. Energy difference can be as large as 4.9 kcal mol ^-1 for the reaction by using aug-cc-pvdz and 6-31++G** basis sets respectively.