## "What would you do with the exact functional? Probing the limits of density functional theory (DFT)"Miles Stoudenmire
, Perimeter Institute
[Host: Paul Fendley]
ABSTRACT:
Density functional theory (DFT) is a very successful method for computing properties of realistic many-electron systems applied across condensed matter and materials physics. It is based on exact principles, but using it in practice requires approximations. Unfortunately, present approximations have systematic drawbacks, such as failing to produce accurate charge gaps for strongly correlated systems or predicting spurious magnetic order.
To understand DFTâs potential and limitations, we have extended the powerful density matrix renormalization group (DMRG) technique to solve one-dimensional continuum electron systems with realistic interactions. Such systems are also interesting in their own right (in the context of cold atom experiment, for example). With our ability to solve these systems essentially exactly, we have even implemented the exact functional at the heart of DFT. I will discuss our results on computing gaps within DFT (both exact and approximate) and a recent proof from our group that Kohn-Sham DFT always converges when using the exact functional. We find that while some drawbacks of DFT can be blamed on approximations, other limitations are fundamental. Yet our work suggests that great progress is possible for applying DFT to strongly correlated systems. |
Condensed Matter SeminarThursday, January 16, 2014 3:30 PM Physics Building, Room 204 Note special room. |

To add a speaker, send an email to phys-speakers@Virginia.EDU. Please include the seminar type (e.g. Condensed Matter Seminars), date, name of the speaker, title of talk, and an abstract (if available).