In the present study, microsolvation and interaction of the CHþ cation with Hen¼111 clusters are investigated by means of ab initio calculations at MP2/aug-cc-pVTZ and QCISD/aug-ccpVTZ levels. Stabilization energies of the studied complexes including basis set superposition error (BSSE) and zero point energy (ZPE) corrections are in the range of 1:8 kJ/mol and 11:6 kJ/mol. A good linear correlation is found between the stabilization energy and stretching frequency shift () in the studied complexes. According to energy decomposition analysis, it is found that polarization e®ects are the major source of the attraction in these complexes.
