Structure and Spectra of Three-Dimensional(H2O)nClusters,n=8,9,10

Abstract

The vibrational OH stretch spectra have been measured for size-selected pure water clusters $({\mathrm{H}}_{2}\mathrm{O}{)}_{n}$, in the size range $n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}8--10$. Comparison between experiment and calculations suggests that the spectra originate from a small number of ``microcrystalline'' structures, based on the cubic octamer. The $n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}8$ spectra are caused by two isomers of ${D}_{2d}$ and ${S}_{4}$ symmetry. The proposed lowest energy nonamer and decamer structures are derived from the octamer by insertion of one and two two-coordinated molecules, respectively, into the cube edges.