Hydration of hydrogentungstate anions at different pH conditions:: A Car-Parrinello molecular dynamics study

Standard density functional theory calculations with a continuous model of solvation as well as Car-Parrinello molecular dynamics simulations with explicit solvent molecules are carried out to analyze the effect of the pH of the solution on the coordination sphere of the W-VI ion. Both methodologies agree in predicting an expansion of the coordination sphere of the W-VI ion upon a decrease in the pH. Continuous solvation models, however, are unable to predict as stable some structural isomers of a hydrated hydrogentungstate anion and tungstic acid.