Electronic-structure challenges in materials modeling for energy applications
- Nicola Marzari (Swiss Federal Institute of Technology, Lausanne, Switzerland)
- Angel Rubio (University of the Basque Country, San Sebastian, Spain)
Many of the topics and properties related to the workshop theme areat the frontier of what is currently possible with electronic-structure modeling.
1. Accurate exchange correlation functionals, covering topics such as dispersion forces, or self-interactions: several groups have made great progress in modeling dispersion forces, from the pioneering Lundqvist/Langreth effort, to more recent efforts in Davis (Galli), Trieste (de Gironcoli), and Wien (Kresse), to cite only a few, using RPA and/or the adiabatic connection. Progress in self-interaction free functionals has been slower, with studies by Spaldin (UCSB) and Tsemekhmann (PNNL) on the Perdew-Zunger functional, together with recent developments on the calculations of U and V parameters from first-principles (e.g. Coccioni, U. of Minnesota) or on more broadly-applicable self-interaction free functionals (Yang (Duke) and Dabo (Cermics, Paris)). Very relevant also for strongly-correlated systems (Gross (Berlin)).
2. charge-transfer reactions: these are challenging to the non-local nature of the excitations; in the context of DFT they have been studied e.g. in the group of Rubio (UPV) and Maitra (Hunter college); notable is also the intrudction of constrained functionals (especially Van Voorhis (MIT), but also Marzari (MIT) and Scheffler/Behler (FHI)).
3. reactions in the presence of an electrochemical potential: pioneering work by Norskov (DTU) and Sprik (U Cambridge).
4. electrical and thermal transport: work on Landauer and NEGF is very well established. Much less on inelastic effects in electronic transport (Mauri, Paris VI) and on thermal transport (Mingo (CEA), Broido (Boston College), Galli (UC Davis)).
5. optical absorption and exciton formation: a very active area, with pioneering efforts in Europe (Godby (York), Reining (Paris), Del Sole (Roma), Molinari (Modena), Rincke/Scheffler (FHI), Gonze (Louvain), and many others) and the US (Louie (Berkeley), Hybertsen (BNL), van Schilfgaarde (ASU)). Interesting recent developments in large-scale techniques (Umari (Trieste), and very lively interaction between issues in GW and TDDFT approaches.
6. ion dynamics in an excited state: a very difficult problem, with e.g. pioneering efforts by Martinez (Stanford), or in combined electronic and ionic dynamics by Horsfield (Imperial College)
7. catalytic activity of open-shell systems: abundandt DFT failures, even using hybrid functionals. Closely studied by Truhlar (Minnesota) and the chemistry community (e.g. Siegbahn, Stockholm). In DFT, recent efforts by Marzari (MIT), Oppeneer (Uppsala), using generalized Hubbard techniques