Ab initio SCF and MP2 calculations have been performed on the structur
al and energetic properties of H2O-2CO. Three possible energy minima w
ere found, all forming almost linear hydrogen bonds. The most stable s
pecies was observed when both carbon monoxide monomers were attached t
o water via the carbons. An energy decomposition analysis was performe
d on various complexes in order to study the nature of the intermolecu
lar interactions. The co-operative effects in the different species ar
e found to be negligible.