DFT studies on the β-glycosidase catalytic mechanism: The deglycosylation step

The performance of a wide variety of DFT functionals was also investigated. Density functionals of the different classes, namely, meta-generalized gradient approximation (meta-GGA), hybrid-GGA and hybrid-meta-GGA density functionals were tested. The DFT results were compared with high-level ab initio calculations carried out at the MP2, MP3, MP4 and QCISD(T) levels of theory.