Variational Treatment of the HeH+ Ion and the β-Decay in HT

The nonrelativistic energies of the HeH+ ion have been computed by the variational method for the ground state and for the first excited 1Σ+ state. The wavefunction employed was a 64-term generalized James—Coolidge expansion. The computed binding energy of the ground state amounts to De=16448.3 cm−1 at the equilibrium separation Re=1.46324 a.u. The excited state is found to be repulsive. The HeH+ wavefunctions are used to compare quantitatively the theory of β-decay in molecules with experiment. It is shown that for the HT molecule, the theory predicts the dissociation in at least 17.8% of the events while the corresponding experimental number is 6.8%±1.9%.