Helium nanodroplets are doped with cesium and molecular hydrogen and subsequently ionized by electrons. Mass spectra reveal HxCs+ ions that contain as many as 130 hydrogen atoms. Two features in the spectra are striking: First, the abundance of ions with an odd number of hydrogen atoms is very low; the abundance of HCs+ is only 1 % that of H2Cs+. The dominance of even-numbered species is in stark contrast to previous studies of pure or doped hydrogen cluster ions. Second, the abundance of (H2)nCs+ features anomalies at n = 8, 12, 32, 44, and 52. Guided by previous work on ions solvated in hydrogen and helium we assign the anomalies at n = 12, 32, 44 to the formation of three concentric, solid-like solvation shells of icosahedral symmetry around Cs+. Preliminary density functional theory calculations for n ≤ 14 are reported as well.
@article{arxiv.1805.00809,
title = {Cs$^{+}$ Solvated in Hydrogen - Evidence for Several Distinct Solvation Shells},
author = {Lorenz Kranabetter and Marcelo Goulart and Abid Aleem and Thomas Kurzthaler and Martin Kuhn and Erik Barwa and Michael Renzler and Lukas Grubwieser and Matthias Schwärzler and Alexander Kaiser and Paul Scheier and Olof Echt},
journal= {arXiv preprint arXiv:1805.00809},
year = {2018}
}