The nature of the chemical bond in sodium tungstate based on ab initio, DFT and QTAIM topological analysis of electron density

Abstract

Abstract In the present study, we carried out a detailed study of interactions in sodium tungstate dihydrate [Na2WO4·2H2O] using computational methods. The solid-state DFT calculations carried out on accurately re-determined crystal structure of sodium tungstate dihydrate using positional parameters obtained from single crystal diffraction experiment. The Energies of interatomic and intermolecular interactions, the hydrogen bonds in particular, are estimated as Eint ≈ −0.5Vb. The topological properties based on Bader’s theory of atoms in molecules using AIMALL program employed to evaluate the interaction energies. Also the parameters such as electron density (ρ), Laplacian (∇2ρ), local potential energy (Vb), and kinetic potential energy (Gb) at bond critical points were obtained for all the non-covalent interactions. Among the number of non-bonding Na…O ionic interactions, the hydrate mediated O–H…O hydrogen bond found to be stronger with interaction energy of 24.46 kJ/mol.