Scientific Achievement

An experimental and theoretical study of protonated water clusters revealed a new magic number of 14 water molecules solvating the hydronium ion (H3O+).

Significance and Impact

Discovery impacts research in environmental science, nucleation, solvation and low temperature chemistry.

Research Details

An experimental strategy employing synchrotron based threshold photoionization coupled to the ability to ionize water clusters within an supersonic expansion allowed us to prepare an unique metastable distribution of protonated water clusters. The results show that H+(H2O)14 is particularly stable under these conditions. A careful computational search for the most stable conformer of protonated water clusters from n = 2 to 22 using metadynamics methods followed by refinement with density functional methods revealed that while n=21 is magic, n=14 is also stable compared to its neighbors.

Publication Details

Mackie, C. J.; Lu, W. C.; Liang, J.; Kostko, O.; Bandyopadhyay, B.; Gupta, I.; Ahmed, M.; Head-Gordon, M. “Magic Numbers and Stabilities of Photoionized Water Clusters: Computational and Experimental Characterization of the Nanosolvated Hydronium Ion.” J. Phys. Chem. A 2023.
DOI 10.1021/acs.jpca.3c02230