Comp Chem Research Developments

The ubiquitous nature of water has prompted great interest in using simulation techniques, such as molecular dynamics and Monte Carlo methods, to better understand the structure and properties of liquid water and ice. Recent attention has focused on using density functional theory (DFT) as a means to study these systems, however the high expense of these simulations has restricted the choice of available density functionals to less costly, and often, less accurate, methods.

Graduate student Erin Dahlke and Professor Donald Truhlar have compared a series of 25 density functional methods to highly accurate ab initio data for a set of 28 water dimers and 8 water trimers, in order to assess the accuracy of existing density functional methods and to learn the features needed for improved accuracy. As a result of this experience they have gone on to optimize a new functional, PBE1W, that achieves accuracy equal to that of the best existing (and more costly DFT methods) while retaining the cost-effectiveness of those methods currently in use for condensed-phase simulation.

Additional work is ongoing. This research is supported in part by the NSF.