Density functional study of the Xe2H3+ cation

A density functional theory investigation has been carried out to determine the equilibrium geometry, binding energy and vibrational properties of Xe2 H3+. The molecule is a linear centrosymmetric species with a dissociation e nergy of similar to 80 kJ mol(-1) corresponding to the dissociation limit o f Xe2H+ and two hydrogen atoms. At the B3LYP/aug-cc-pVQZ level employing 18 -VE effective core potential on xenon the terminal Xe-H bonds are predicted to be shorter (1.7149 Angstrom) than the Xe-H bonds involving the center h ydrogen (2.1298 Angstrom). Computationally the most strongest vibrational b and involves a Xe-H stretch of the center hydrogen inducing an extremely st rong band at 1163 cm(-1). The bonding properties of Xe2H3+ have been studie d according to topological analysis of the electron localization function ( ELF), which indicate that the terminal hydrogens are bound by covalent inte ractions. The center hydrogen is bound to the neighboring xenons mainly by electrostatic forces even though a non-negligible fraction of covalent natu re is found. (C) 1999 Elsevier Science B.V. All rights reserved.