The He 2 + 2 molecular ion can exist in a magnetic field

Abstract A detailed study of the ground state of the Coulomb system (ααee) which corresponds to the He 2 molecular ion in a magnetic field B = 0− 4.414× 10 13 G in parallel configuration (infinitely massive α−particles are situated along a magnetic field line) is presented. The variational method is employed using a trial function which includes electronic correlation in the form exp (γr12) where γ is a variational parameter. It is shown that the quantum numbers of the lowest total energy state depend on the magnetic field strength. It evolves from the spin-singlet Σg metastable state at 0 ≤ B . 0.85 a.u. to a repulsive spin-triplet Σu state for 0.85 a.u. . B . 1100 a.u. and, finally, to a strongly bound spin-triplet Πu state at stronger fields B & 1100 a.u.