Fluctuations and bonding in lithium clusters

Structures and bonding of the Li-8 and Li-20 clusters are investigated with path integral simulations combined with electronic structure calculations. The zero-point motion of the nuclei leads to quantum fluctuations corresponding to about 100 K thermal excitations. This destroys the distinction between long and short bonds which is a characteristic feature of the optimized static structures, but does not induce a qualitative change in the duster structures or their electronic properties.