Quantum Monte Carlo study of large spin-polarized tritium clusters

This work expands recent investigations in the field of spin-polarized tritium (T downward arrow) clusters. We report the results for the ground-state energy and structural properties of large T downward arrow clusters consisting of up to 320 atoms. All calculations have been performed with variational and diffusion Monte Carlo methods, using an accurate ab initio interatomic potential. Our results for N < or = 40 are in good agreement with results obtained by other groups. Using a liquid-drop expression for the energy per particle, we estimate the liquid equilibrium density, which is in good agreement with our recently obtained results for bulk T downward arrow. In addition, the calculations of the energy for large clusters have allowed for an estimation of the surface tension. From the mean-square radius of the drop, determined using unbiased estimators, we determine the dependence of the radii on the size of the cluster and extract the unit radius of the T downward arrow liquid.