Rung 3.5 density functionals: Another step on Jacob's ladder


  • Benjamin G. Janesko received a Ph. D. in 2005, working with David J. Yaron at Carnegie Mellon University. He performed postdoctoral research with Gustavo E. Scuseria at Rice University. Since 2009, he has been an assistant professor of chemistry at Texas Christian University. His group develops new approximate exchange-correlation functionals for density functional theory, and applies computational chemistry tools to heterogeneous catalysis, cross-coupling catalysis, conjugated polymers, and related problems in energy technology. [Color figure can be viewed in the online issue, which is available at]


Applications of density functional theory (DFT) to computational chemistry and solid-state physics rely on a “Jacob's Ladder” of progressively more complicated approximations to the many-body exchange-correlation (XC) density functional. Accurate, computationally tractable DFT calculations on large and periodic systems remain challenging for existing XC functionals. Simple XC functionals on the three lowest rungs of Jacob's Ladder are insufficiently accurate for many properties, while fourth-rung hybrid functionals incorporating nonlocal information can be prohibitively expensive. This perspective presents our work toward a compromise, a new class of “Rung 3.5” functionals that incorporate a linear dependence on the nonlocal one-particle density matrix. This work reviews these functionals' formal underpinning, numerical performance, and prospects for modeling solids and surfaces. © 2012 Wiley Periodicals, Inc.