Heat of formation of the SiF2++ dication: a theoretical prediction

Energetics of the SiF2+ + dication and fragments related to it, SiF+ + and SiF+, was calculated using different ab initio approaches, including the se miempirically corrected G2, the complete basis set method, and the coupled cluster method up to the CCSD(T)/aug-cc-pVQZ level. The calculated values o f bond energies and ionization potentials were carefully compared with the available experimental data to assess the accuracy of these approaches. In addition, reaction enthalpies for possible fragmentation reactions were cal culated. The heat of formation of the SiF2+ + dication, resulting from thes e calculations, is Delta H-f(SiF2+ +) = 546 +/- 2 kcal/mol and a theoretica l estimate of Delta H-f(SiF+ +) is 649 +/- 2 kcal/mol. (C) 1999 Elsevier Sc ience B.V.