Collect. Czech. Chem. Commun. 2008, 73, 1271-1280

About Non-Existence of the Molecular Ion H3++

Héctor Medel-Cobaxina,*, Alexander Alijahb and Alexander V. Turbinera

a Instituto de Ciencias Nucleares, UNAM, Apartado Postal 70-543, 04510 México
b Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal


It is shown that the molecular ion H3++ does not exist in a form of the equilateral triangle. To this end, a compact variational method is presented which is based on a linear superposition of six specially tailored, Coulomb-type trial functions containing non-linear parameters. Careful optimization of a total of fifteen parameters gives consistently lower variational results for the electronic energy than can be obtained with standard methods of quantum chemistry even with huge basis sets as large as mcc-pV7Z. Taking the proton (electron) charge as a continuous parameter the critical charges are found where the ion H3++ becomes (meta)-stable.

Keywords: Hydrogen; Trihydrogen dication; Coulomb-type trial functions; Schrödinger equation; Born-Oppenheimer approximation; Ab initio calculations.

References: 25 live references.