Modeling fast electron dynamics with real-time time-dependent density functional theory: application to small molecules and chromophores

Journal Article · Tue May 10 00:00:00 EDT 2011 · Journal of Chemical Theory and Computation, 7(5):1344-1355

DOI:https://doi.org/10.1021/ct200137z· OSTI ID:1022426

Lopata, Kenneth A; Govind, Niranjan

The response of matter to external fields forms the basis for a vast wealth of fundamental physical processes ranging from light harvesting to nanoscale electron transport. Accurately modeling ultrafast electron dynamics in excited systems thus o_ers unparalleled insight, but requires an inherently non-linear time-resolved approach. To this end, an e_cient and massively parallel real-time real-space time-dependent density functional theory (RT-TDDFT) implementation in NWChem is presented. The implementation is first validated against linearresponse TDDFT and experimental results for a series of molecules subjected to small electric field perturbations. Second, non-linear excitation of green fluorescent protein is studied, which shows a blue-shift in the spectrum with increasing perturbation, as well as a saturation in absorption. Next, the charge dynamics of optically excited zinc porphyrin is presented in real-time and real-space, with relevance to charge injection in photovoltaic devices. Finally, intermolecular excitation in an adenine-thymine base pair is studied using the BNL range separated functional [Baer, R.; Neuhauser, D. Phys. Rev. Lett. 2005, 94, 043002], demonstrating the utility of a real-time approach in capturing charge transfer processes.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1022426
• Report Number(s): PNNL-SA-78077; 42591; KP1704020; TRN: US201117%%857
• Journal Information: Journal of Chemical Theory and Computation, 7(5):1344-1355, Vol. 7, Issue 5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ABSORPTION
BNL
ELECTRIC FIELDS
ELECTRONS
EXCITATION
DENSITY FUNCTIONAL METHOD
HARVESTING
IMPLEMENTATION
PORPHYRINS
PROTEINS
SATURATION
SIMULATION
TRANSPORT
ZINC
Quantum mechanics
Excited states
Spectroscopy
TDDFT
Environmental Molecular Sciences Laboratory