Bulletin of the American Physical Society
APS March Meeting 2012
Volume 57, Number 1
Monday–Friday, February 27–March 2 2012; Boston, Massachusetts
Session W35: Focus Session: DFT VIII: Time-Dependent Processes II: Excitations
11:15 AM–2:15 PM,
Thursday, March 1, 2012
Sponsoring Unit: DCP
Chair: Neepa Maitra, Hunter College, CUNY
Abstract ID: BAPS.2012.MAR.W35.1
Abstract: W35.00001 : Watching excitons move: the time-dependent transition density matrix*
11:15 AM–11:51 AM
Preview Abstract Abstract
(University of Missouri)
Time-dependent density-functional theory allows one to calculate excitation energies and the associated transition densities in principle exactly. The transition density matrix (TDM) provides additional information on electron-hole localization and coherence of specific excitations of the many-body system. We have extended the TDM concept into the real-time domain in order to visualize the excited-state dynamics in conjugated molecules. The time-dependent TDM is defined as an implicit density functional, and can be approximately obtained from the time-dependent Kohn-Sham orbitals. The quality of this approximation is assessed in simple model systems. A computational scheme for real molecular systems is presented: the time-dependent Kohn-Sham equations are solved with the OCTOPUS code and the time-dependent Kohn-Sham TDM is calculated using a spatial partitioning scheme. The method is applied to show in real time how locally created electron-hole pairs spread out over neighboring conjugated molecular chains. The coupling mechanism, electron-hole coherence, and the possibility of charge separation are discussed.
*This work is supported by NSF Grant DMR-1005651.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.MAR.W35.1
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