Non-Born-Oppenheimer study of positronic molecular systems: e ⁺LiH

The ground state of e ⁺LiH was discussed to measure non-Born-Oppenheimer (BO) variational approximations using correlated Gaussian functions with preexponential factors. The non-BO energies of HPs, LiH and Li ⁺ were also determined to calculate positron detachment energy of e ⁺LiH and dissociation energy corresponding to e ⁺LiH fragmentation into HPs and Li ⁺. The lowest variational upper-bounds to ground state energies were observed for all systems. The e ⁺LiH dissociation energy was found to be 0.036548 hartree and annihilation rates of HPs and e ⁺LiH were also calculated.