Assessment of density functional methods for thermochemistry of chromium oxo compounds and their application in a study of chromia–silica system

Performance of GGA, meta-GGA, hybrid GGA and hybrid meta-GGA DFT methods in predicting relative energies of gas phase chromium oxo compounds is studied. The most accurate functionals are PW91, mPWKCIS, PBE, MPWLYP1M, BP86, M06-L and VSXC. operties and relative energies of isolated Cr(VI) oxo species on silica have been further investigated applying three DFT methods in parallel. For the silica model used in this work, it is predicted that both monooxo and dioxo Cr(VI) species can be present in CrO3/SiO2 system under dehydrated conditions.