Proton transport in water: Ab initio molecular dynamics simulations performed in the complete basis set limit

CHED 346

Timothy C. Berkelbach, tcb244@nyu.edu, Hee-Seung Lee, hls240@nyu.edu, and Mark E. Tuckerman, mark.tuckerman@nyu.edu. Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003
The structural and dynamical properties of an excess proton in liquid water were studied via Car-Parrinello ab initio molecular dynamics. Electronic structure was treated with Kohn-Sham (KS) density functional theory using the Becke-Lee-Yang-Parr exchange-correlation functional. The KS orbitals were expanded using a discrete variable representation (DVR), to be contrasted with prior studies, which employed a plane-wave (PW) basis set expansion. The use of DVRs has been shown to yield properties very close to the complete basis set limit, allowing for the systematic elimination of errors arising from improper convergence. Utilized here, this methodology yields structural and dynamical properties of bulk water in much better agreement with experiment than previous PW studies, predicting more liquid-like radial distribution functions and diffusion constants.