Quantum Chemistry Study On Cooperative Effect Of Hydrogen Bonds In 5¹² Single Cage Water Clusters

The cooperative effect of hydrogen bond has been thought to play a crucial role in all kinds of water molecular clusters.It not only significantly affects the binding energy of water molecules,but also determines the stability of water clusters.By constructing a large number of 512 single cage clusters and investigating its varied hydrogen-bonding networks,we discussed the distribution of the energy of hydrogen bonding networks,and the cooperative effects of 5 groups and 74 sub-grouped hydrogen bonds.The results show that the binding energy of 512 single cage cluster hydrogen bond network increases with the number of class 1221 sub-grouped hydrogen bonds contained in the cluster.In combination with Anick's list,we found that the binding energy increases with the number of 21-type waters of first class and second class,decreased with the number of 21-type waters of third class and fourth class.The average bond energy of the class 1221 sub-grouped hydrogen bonds is the highest,and the average bond energies of the remaining three classes,1212,2112,and 2121 are similar.The distribution of bond energy in the same class of sub-grouped hydrogen bonds is also different,in general,donor fragment or acceptor fragment sharing identical value of three independent digits usually performs poor cooperative effect,indicating that the existence of those same-digital-array fragments is the necessary condition to judge poor cooperative effect.On the contrary,the existence of different-digital-array is also the necessary condition to judge strong cooperative effect.