Density functional theory study of formaldehyde oligomers

Hydrogen-bonded formaldehyde oligomers (dimer to pentamer) are studied using density functional theory (DFT), the B3LYP method, and the 6-311+G* basis set. Many-body interaction energies are obtained to study the contribution of many-body terms to binding energy. The basis set superposition error (BSSE)-corrected total energies are -229.08170, -343.61410, -458.16660, and -572.70901 hartrees for dimer, trimer, tetramer, and pentamer, respectively, with corresponding binding energies -2.55, -4.86, -6.99, and -9.49 kcal/mol. Two-body energies have been found to contribute significantly to the total binding energy in dimer to pentamer, whereas higher-order interaction energies are negligible. (C) 2004 Wiley Periodicals, Inc.