Ab initio molecular-dynamics simulation of concentrated phosphoric acid

We have investigated the properties of 100% phosphoric acid (H3PO4) in the liquid state by the combination of gradient-corrected density-functional theory and norm-conserving pseudopotentials. Various structural properties as well as the vibrational density of states have been calculated through molecular-dynamics simulations under the Born-Oppenheimer approximation. Proton transfer is found to occur frequently between adjacent PO4 groups along the OH center dot center dot center dot O hydrogen bonds, which makes the single and double bonds indistinguishable.