THE GROUND-STATE OF (HE-H-HE)(-INITIO CALCULATIONS() FROM CORRELATED AB)

He2H+ ion in its ground state is studied by means of ab initio methods taking into account the electron correlation. Geometry optimization a t the CCSD(T)/cc-pV5Z level of theory has been performed and the poten tial energy hypersurface scan is presented. The optimum conformation i s linear and symmetric with the proton at the He-He midpoint and the H e-H distance equal to 1.75 bohr. Stabilization energy with respect to the He2H+ --> HeH+ + He dissociation channel has been computed. Additi onally, a single point variational calculations with the use of the Ex ponentially Correlated Gaussian wave functions have been performed. Th ey supply an upper bound to both the total electronic energy (-5.90350 5 hartree) and the stabilization energy (-13.224 kcal/mol). A comparis on of the results from both the perturbational coupled cluster and var iational methods is presented.