Clusters of glycolic acid and 16 water molecules

Semiempirical, ab initio and density functional theory calculations are used to locate many low-energy minima on the potential energy surface of the CH2OHCOOH–(H2O)16 complex. The lowest-energy structures consist of a fused, pentagonal-prism (H2O)16 cluster hydrogen-bonded to the carboxylic group of the glycolic acid; the intramolecular hydrogen bond remains intact in the glycolic acid. Low-energy structures with the acid inside a cage-like water cluster were not found.