Assessment of different basis sets and DFT functionals for the calculation of structural parameters, vibrational modes and ligand binding energies of Zr4O2(carboxylate)12 clusters

Different basis sets and functionals in the framework of Density Functional Theory (DFT) were assessed for an accurate prediction of structural parameters and vibrationalmodes of the cluster Zr4O2(methacrylate)12. A basis set of at least triple-n quality is necessary to accuratelymodel the geometry and the IR spectra. Bond distances are best reproduced with hybrid functionals, while IR frequencies are best described by the generalized gradient approximation family of functionals. LDA functionals give thehighestGGA functionals the lowest ligand binding energies. Increasing the amount of Hartree Fock exchange in the hybrid functionals results in higher binding energies. Binding energies of ligands in different positions of Zr4O2(methacrylate)12 were calculated. The ligand binding energy decreases when the H atoms in an acetate ligand are successively replaced by F atomswith concomitant lengthening of the Zr–Obond. A chelating acetylacetonate ligand shows a higher ligand binding energy than chelating carboxylate ligands. 2016 The Authors. Published by Elsevier B.V. This is anopenaccess article under the CCBY license (http:// creativecommons.org/licenses/by/4.0/).