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Multistage ab initio quantum wavepacket dynamics for electronic structure and dynamics in open systems: momentum
Alexander B Pacheco1, Srinivasan S Iyengar
1Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
The Journal of Chemical Physics
|February 24, 2011
Summary
We expanded a computational method to simulate electron transport in molecular wires, now including nuclear motion and electromagnetic fields. This allows for more accurate modeling of electron dynamics in complex nanoscale systems.
Area of Science:
- Computational Chemistry
- Quantum Dynamics
- Nanoscale Science
Background:
- Electron transport in molecular systems is crucial for nanoelectronic devices.
- Accurately modeling delocalized electronic systems and donor-bridge-acceptor architectures is challenging.
- Existing methods often simplify nuclear dynamics or external field interactions.
Purpose of the Study:
- To extend the multistage ab initio wavepacket dynamics (MS-AIWD) method.
- To incorporate simultaneous nuclear dynamics and external electromagnetic fields into the MS-AIWD treatment.
- To provide a more comprehensive simulation of electron transport in open electronic systems.
Main Methods:
- The generalized MS-AIWD method partitions the donor-bridge-acceptor system.
- Absorbing and emitting boundary conditions account for electronic coupling with electrodes.
- Wavepacket propagation is analyzed in the momentum representation.
Main Results:
- The extended MS-AIWD method successfully simulates wavepacket dynamics including nuclear motion and external fields.
- Analysis of an Al(27)-C(7)-Al(27) nanowire model reveals wavepacket momentum dependence on external bias.
- Transmission probabilities are shown to be sensitive to the applied external field magnitude.
Conclusions:
- The enhanced MS-AIWD method offers a powerful tool for studying electron transport in realistic molecular systems.
- Simultaneous treatment of electronic and nuclear dynamics under external fields is essential for accurate simulations.
- This advancement facilitates the design and understanding of molecular electronic devices.
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