@article{pittir18123,
          volume = {304},
          number = {5674},
           month = {May},
          author = {JW Shin and NI Hammer and EG Diken and MA Johnson and RS Walters and TD Jaeger and MA Duncan and RA Christie and KD Jordan},
           title = {Infrared signature of structures associated with the H{\ensuremath{<}}sup{\ensuremath{>}}+{\ensuremath{<}}/sup{\ensuremath{>}}(H {\ensuremath{<}}inf{\ensuremath{>}}2{\ensuremath{<}}/inf{\ensuremath{>}}O){\ensuremath{<}}inf{\ensuremath{>}}n{\ensuremath{<}}/inf{\ensuremath{>}} (n = 6 to 27) clusters},
         journal = {Science},
           pages = {1137 -- 1140},
            year = {2004},
             url = {http://d-scholarship-dev.library.pitt.edu/18123/},
        abstract = {We report the OH stretching vibrational spectra of size-selected H +(H2O)n clusters through the region of the pronounced "magic number" at n = 21 in the cluster distribution. Sharp features are observed in the spectra and assigned to excitation of the dangling OH groups throughout the size range 6 {$\leq$} n {$\leq$} 27. A multiplet of such bands appears at small cluster sizes. This pattern simplifies to a doublet at n = 11, with the doublet persisting up to n = 20, but then collapsing to a single line in the n = 21 and n = 22 clusters and reemerging at n = 23. This spectral simplification provides direct evidence that, for the magic number cluster, all the dangling OH groups arise from water molecules in similar binding sites.}
}