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Updated: Jun 24, 2025
Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Nonadiabatic molecular dynamics with subsystem density functional theory: application to crystalline pentacene
Qingxin Zhang1, Xuecheng Shao2, Wei Li3
1Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY 14260, United States of America.
We developed a new computational method for simulating excited-state dynamics in large materials. This approach reveals that structural disorder accelerates energy relaxation in pentacene crystals, with specific methods accurately predicting slower recovery rates.
Area of Science:
- Computational Chemistry
- Materials Science
- Quantum Mechanics
Background:
- Nonadiabatic molecular dynamics are crucial for understanding excited-state processes in materials.
- Simulating large systems requires efficient electronic structure calculations.
- Accurate modeling of energy relaxation is key to designing new materials.
Purpose of the Study:
- To develop and assess a novel nonadiabatic molecular dynamics approach for large condensed-matter systems.
- To investigate the dynamics of nonradiative relaxation in pentacene crystals.
- To compare various quantum-classical trajectory surface hopping schemes.
Main Methods:
- Development of a nonadiabatic molecular dynamics approach using linearly scaling subsystem density functional theory.
- Implementation in open-source Quantum Espresso/Libra software for extended systems.
- Simulation of pentacene crystals using supercells with over 600 atoms.
Main Results:
- Increased structural disorder in larger supercells enhances nonadiabatic couplings and accelerates excited-state relaxation.
- Most tested surface hopping schemes predict fast energy relaxation (0.7-2.0 ps) but overestimate ground state recovery.
- The modified simplified decay of mixing approach accurately predicts slower relaxation (8-14 ps) and inhibited ground state recovery.
Conclusions:
- The developed computational method is applicable to large condensed-matter systems.
- Structural disorder plays a significant role in excited-state dynamics.
- Accurate prediction of relaxation timescales requires careful selection of surface hopping schemes.
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