title: The heat of formation of gaseous PuO(2)2+ from relativistic density functional calculations.
abstract: Using a set of model reactions, we estimated the heat of formation of gaseous PuO2(2+) from quantum-chemical reaction enthalpies and experimental heats of formation of reference species. To this end, we carried out relativistic density functional calculations on the molecules PuO(2)2+, PuO2, PuF6, and PuF4. We used a revised variant (PBEN) of the Perdew-Burke-Ernzerhof gradient-corrected exchange-correlation functional, and we accounted for spin-orbit interaction in a self-consistent fashion. As open-shell Pu species with two or more unpaired 5f electrons are involved, spin-orbit interaction significantly affects the energies of the model reactions. Our theoretical estimate for the heat of formation DeltafH degree 0(PuO2(2+),g), 418+/-15 kcal mol-1, evaluated using plutonium fluorides as references, is in good agreement with a recent experimental result, 413+/-16 kcal mol-1. The theoretical value connected to the experimental heat of formation of PuO2(g) has a notably higher uncertainty and therefore was not included in the final result.
authors.affiliation: Department Chemie, Theoretische Chemie, Technische Universität München, 85747, Garching, Germany.
authors.forename: Lyudmila V
authors.initials: LV
authors.lastname: Moskaleva
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Matveev
authors.forename: Joachim
authors.initials: J
authors.lastname: Dengler
authors.forename: Notker
authors.initials: N
authors.lastname: Rösch