Shapes of 3He clusters.

Triaxial deformations are considered for determining the binding energies of open-shell, unpolarized HeN clusters. The shapes of He clusters are found to be close to spherical, in contrast to the well-deformed shapes of alkali-metal clusters. As a result, odd-even alternations and subshell closures between major shells are absent in the size evolution of the chemical potentials, and the second-energy differences associated with HeN clusters. @S0163-1829~96!00735-7#