Many-body interactions of carbon monoxide cyclic oligomers: A computational study

摘要

Structural properties and energetics for the optimized carbon monoxide cyclic oligomers are analyzed at the correlated ab initio second-order Moller-Plesset (MP2) and density functional methods (B3LYP and mPW1PW), using Dunning's ccp-VXZ (X = D, T, Q) basis set, augmented with diffuse functions. Many-body interactions of the stable carbon monoxide cyclic oligomers, (CC), and (CO), are computed at the MP2/aug-cc-pVTZ level. Contributions of two- to five-body terms to each of these oligomers for their interaction energies, including corrections for basis set superposition error (BSSE) are investigated by using function counterpoise and its generalized version. It has been found that three-body terms are attractive in nature and essential in order to describe the cooperative effects in the stable cyclic CO oligomers. (c) 2005 Wiley Periodicals, Inc.