engleski

Ground state properties of the small mixed helium clusters

The ground state energy and structure of helium mixed clusters $^3$He$_{; ; 2, 3, 4}; ; $$^4$He$_2$, $^3$He$_{; ; 2, 3, 4}; ; $$^4$He$_3$, $^3$He$_{; ; 2, 3, 4}; ; $$^4$He$_4$ and $^3$He$_{; ; 2, 3}; ; $$^4$He$_5$, consisting of up to 8 helium atoms are calculated using variational and diffusion Monte Carlo procedure. For clusters with three and four $^3$He atoms released node diffusion Monte Carlo procedure is used. The particle separation distribution functions are obtained using unbiased estimators. Our calculations show that clusters $^3$He$_{; ; 3, 4}; ; $$^4$He$_2$ have within errorbars the same binding energy as the cluster $^3$He$_2$$^4$He$_2$, and that $^3$He$_3$$^4$He$_3$ has the same binding energy as $^3$He$_2$$^4$He$_3$. The clusters $^3$He$_{; ; 3, 4}; ; $$^4$He$_2$ and $^3$He$_3$$^4$He$_3$ are in states in which one or two $^3$He atoms are far away from the rest of the system. Other considered clusters are bound. The calculations are performed using several different interatomic potentials and the conclusions concerning stability are insensitive to the particular form of the interaction potential. We compare our results with the recent experiment and other theoretical calculations.

3He-4He mixtures; clusters; Monte Carlo

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