Variational Monte Carlo Calculations for Spin-Aligned Deuterium

The first variational Monte Carlo calculations of the ground-state energy of spin-aligned deuterium D{↓} are presented. Using Slater-Jastrow trial wave functions, the calculations are based on the accurate theoretical pair potential of Kolos and Wolniewicz for the b³Σᵤ⁺ state. For D{↓} with equal population of the three nuclear-spin states, the minimum theoretical ground-state energy is found to be negative, implying that this system is a liquid at zero temperature under zero external pressure.