Quantum Monte Carlo study of large spin-polarized tritium clusters

Abstract

This work expands recent investigations in the field of spin-polarized tritium ͑T↓͒ clusters. We report the results for the ground-state energy and structural properties of large T↓ 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 Յ 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↓. 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↓ liquid.

One dimensional1H,2H and3H

“…A further advantage of considering polarized hydrogen is that its interatomic potential is exactly known from works by Kolos, Jamieson, Dalgarno, and Wolniewicz [12,13,14]. As the model potential is the only input of quantum Monte Carlo methods, we can benefit of its power for producing very accurate quantitative results [15][16][17][18][19].…”

Spin-polarized hydrogen and its isotopes: A rich class of quantum phases (Review Article)

“…1. In the last years, in most studies of spin-polarized hydrogen and its isotopes the JDW interaction has been used [23][24][25][26][27][28][29][37][38][39][40][41], which is plotted as a solid line in Fig. 1.…”

“…The ground-state properties of spin-polarized tritium T↓ were investigated recently with quadratic DMC and the very precise triplet pair potential 3 u b + Σ [24,28]. The liquid phase was studied in the density interval between the spinodal and freezing densities.…”

“…To examine whether the liquid-drop formula can be applied to (T ) N ↓ clusters, the DMC results for the energy per particle for clusters having from 20 to 320 atoms were fitted in to the liquid-drop model (23) (Ref. 28). The optimal fitting parameters are v E = -3.66(3) K, s E = = 10.2(2) K and c E = -6.1(4) K, and they were obtained without including in the fit the equilibrium liquid T↓ energy per particle 0 e .…”

“…Its liquid and solid phase were studied, and the conditions under which a liquid-solid phase transition occurs in the limit of zero temperature were determined [24]. The large T↓ clusters were also studied and from their ground-state properties several liquid T↓ ground-state properties were extrapolated [28]. As the only representative with the Fermi statistics, spinpolarized deuterium was recently investigated.…”