Quantum disordering versus melting in Lennard-Jones clusters

The ground states of Lennard-Jones clusters for sizes up to n=147 are estimated as a function of the de Boer quantum delocalization length Lambda, and the n-Lambda "phase diagram" is constructed. The increase in Lambda favors more disordered and diffuse structures over more symmetric and compact ones, eventually making the liquidlike motif most energetically favorable. The analogy between the quantum- and thermally-induced structural transitions is explored.