Bonding in cationic MOHn+ (M = K-La, Hf-Rn; n = 0-2): DFT performances and periodic trends

The performances of the DFT functionals B3LYP, BHandHLYP, M06, M06-2X, PBE1PBE, TPSSh, X3LYP, and BP86 have been benchmarked with a thermochemistry database containing 50 bond dissociation energies (BDEs) of M-OH (n) (+) complexes (n = 0-2). Among the tested methods, B3LYP was found to perform best both in accuracy and error distributions. Next, 162 BDEs (M+-OH (n) ) (M = K - La, Hf - Rn; n = 0-2) are calculated at the B3LYP/def2-QZVP level of theory and their periodic trends are presented as an overview. Further, the H-atom affinities of MO+ and MOH+ are derived from the calculated BDEs.