title: Non-Born-Oppenheimer study of positronic molecular systems: e(+)LiH.
abstract: Very accurate non-Born-Oppenheimer variational calculations of the ground state of e(+)LiH have been performed using explicitly correlated Gaussian functions with preexponential factors dependent on powers of the internuclear distance. In order to determine the positron detachment energy of e(+)LiH and the dissociation energy corresponding to the e(+)LiH fragmentation into HPs and Li(+) we also calculated non-BO energies of HPs, LiH, and Li(+). For all the systems the calculations provided the lowest ever-reported variational upper-bounds to the ground state energies. Annihilation rates of HPs and e(+)LiH were also computed. The dissociation energy of e(+)LiH into HPs and Li(+) was determined to be 0.036 548 hartree.
authors.affiliation: Department of Physics and Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA. bubin@email.arizona.edu
authors.forename: Sergiy
authors.initials: S
authors.lastname: Bubin
authors.forename: Ludwik
authors.initials: L
authors.lastname: Adamowicz