High-Level Ab Initio Electronic Structure Calculations of Water Clusters (H₂O)₁₆ and (H₂O)₁₇: A New Global Minimum for (H₂O)₁₆

The lowest-energy structures of water clusters (H2O)16 and (H2O)17 were revisited at the MP2 and CCSD(T) levels of theory. A new global minimum structure for (H2O)16 was found at both the MP2 and CCSD(T) levels of theory, and the effect of zero-point energy corrections on the relative stability of the low-lying minimum energy structures was assessed. For (H2O)17, the CCSD(T) calculations confirm the previously found at the MP2 level of theory “interior” arrangement (fully coordinated water molecule inside a spherical cluster) as the global minimum.