engleski

^3He, ^4He and mixed helium molecules in two dimensions

As a continuation of our previous work, the ground state properties of helium molecules consisting of up to 6 helium atoms in two dimensions (2D) are studied. The calculations are performed using variational and diffusion Monte Carlo (MC) procedures successively. For molecules with more than two ^3He atoms fixed node diffusion MC (DMC) has been employed. A variety of behavior is observed, depending on the number of ^4He and ^3He atoms. Bound states are found for all considered molecules. The binding per particle increases continuously with number of particles for ^4He, but not for ^3He molecules. The particle separation in ^4He molecules is about 10 \AA, while in ^3He molecules it is hundreds of times greater. In mixed molecules, with one or two ^3He atoms, ^3He prefers to stay further away from the center of mass of the molecule than ^4He. In certain cases of mixed molecules, having three and more ^3He atoms, energetics and structure indicate a dimerization of ^3He.

helium molecules; 2D; binding; dimerization

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