Structure of 3He.

Using electron scattering data, the diffraction pattern off [Formula: see text]He shows it to be an equilateral triangle possessing dihedral D[Formula: see text] point group symmetry (PGS). Previous work showed that [Formula: see text]He is a 3-base pyramid with C[Formula: see text] PGS. [Formula: see text]Li is predicted to have C[Formula: see text] PGS. As nuclear [Formula: see text] large, atomic nuclei enter into the 'protein folding problem' with many possible groundstate PGS competing for lowest energy.