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Ground-state path integral Monte Carlo simulations of positive ions in $^4$He clusters: bubbles or snowballs?

Stefano Paolini·Francesco Ancilotto·Flavio Toigo
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Abstract

The local order around alkali (Li$^+$ and Na$^+$) and alkaline-eath (Be$^+$, Mg$^+$ and Ca$^+$) ions in $^4$He clusters has been studied using ground-state path integral Monte Carlo calculations. We apply a criterion based on multipole dynamical correlations to discriminate between solid-like versus liquid-like behavior of the $^4$He shells coating the ions. As it was earlier suggested by experimental measurements in bulk $^4$He, our findings indicate that Be$^+$ produces a solid-like ("snowball") structure, similarly to alkali ions and in contrast to the more liquid-like $^4$He structure embedding heavier alkaline-earth ions.

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Stefano Paolini, Francesco Ancilotto, Flavio Toigo. 2007-01-10. Ground-state path integral Monte Carlo simulations of positive ions in $^4$He clusters: bubbles or snowballs?. https://arxiv.org/abs/cond-mat/0701215

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