Interactions between metal cations with H2 in the M+- H2 complexes: Performance of DFT and DFT-D methods

Abstract

The interactions between metal cations (Ni+, Cu+, Zn+) and H2 molecule have been investigated in detail using dispersion-corrected and -uncorrected double hybrid density functional (DHDF), gradient corrected density functional, ordinary density functional and CCSD(T) methods in conjunction with the correlation consistent triple- ζ quality basis sets. Structural properties, depth of the potential well and dissociation energies are calculated using DFT, DFT-D and CCSD(T) methods and are compared with experimental results. A comparative analysis has been made among DFT, DFT-D and CCSD(T) methods with respect to experiments. The energy components of the interaction energy have been estimated by the symmetry-adapted perturbation theory (SAPT) to analyze the effect of various components on the interaction of the complexes. The dispersion-corrected DHDF, mPW2PLYP-D method shows the best agreement with the experimental values. An NBO analysis has been performed to understand the orbital participation in metal ligand interaction and charge transfer process in these complexes.