Ground-State Properties Of Weakly Bound Helium-Alkali Trimers

Weakly bound triatomic molecules consisting of two helium atoms and one alkali metal atom are studied by means of the diffusion Monte Carlo method. We determined the stability of (4)He(2)A, (4)He(3)HeA, and (3)He(2)A, where A is one of the alkali atoms Li, Na, K, Rb, or Cs. Some of the trimers with He-3 are predicted to be self-bound for the first time, but this is observed to be dependent on the He-A interaction potential model. In addition to the ground-state energy of the trimers, we determined their density, radial, and angular distributions. Many of them are spatially very extended, which qualifies them as quantum halo states. Published by AIP Publishing.