Dicube water dodecamer

Enumeration and classification of hydrogen bond networks

Abstract

Water clusters with a polyhedral framework have many isomers with different hydrogen bond (HB) networks. Although the number of HB networks of various polyhedral water clusters in which every water molecule forms three HBs was reported, little work has been done on the HB networks of water clusters with molecules having four HBs. In this study, we discuss the HB networks of dicubic water dodecamers. The dicube is formed by joining two cubes face to face. All topologically-distinct HB networks of dicubic water dodecamer are presented with a digraph representation. The HB networks are classified into 13 groups based on the numbers of 9 types of HBs formed in the dicubic water dodecamers. Structures of dicubic water dodecamers were produced from the HB networks and were optimized at the MP2/aug-cc-pVDZ level of theory. Although most optimized structures retained initial dicubic HB networks, single HB was broken during the geometry optimization in some structures. We found that there was a common local HB network around the broken HB.