Accurate computational determination of the binding energy of the SO3 x H2O complex

Heike Fliegl; Andreas Glöss; Oliver Welz; Matthias Olzmann; Wim Klopper

doi:10.1063/1.2234372

Accurate computational determination of the binding energy of the SO3 x H2O complex

J Chem Phys. 2006 Aug 7;125(5):054312. doi: 10.1063/1.2234372.

Authors

Heike Fliegl¹, Andreas Glöss, Oliver Welz, Matthias Olzmann, Wim Klopper

Affiliation

¹ Center for Functional Nanostructures (CFN) and Lehrstuhl für Theoretische Chemie, Institut für Physikalische Chemie, Universität Karlsruhe (TH), D-76128 Karlsruhe, Germany.

PMID: 16942218
DOI: 10.1063/1.2234372

Abstract

Reliable thermochemical data for the reaction SO3 + H2O<-->SO3 x H2O (1a) are of crucial importance for an adequate modeling of the homogeneous H2SO4 formation in the atmosphere. We report on high-level quantum chemical calculations to predict the binding energy of the SO3 x H2O complex. The electronic binding energy is accurately computed to De = 40.9+/-1.0 kJ/mol = 9.8+/-0.2 kcal/mol. By using harmonic frequencies from density functional theory calculations (B3LYP/cc-pVTZ and TPSS/def2-TZVP), zero-point and thermal energies were calculated. From these data, we estimate D0 = -Delta H(1a)0(0 K) = 7.7+/-0.5 kcal/mol and Delta H(1a)0(298 K) = -8.3+/-1.0 kcal/mol.