A Real-Time Time-Dependent Density Functional Tight-Binding Implementation for Semiclassical Excited State Electron-Nuclear Dynamics and Pump-Probe Spectroscopy Simulations
| Autor: | Franco P. Bonafé, Thomas Frauenheim, Carlos R. Medrano, Federico J. Hernández, Cristián G. Sánchez, Ben Hourahine, Bálint Aradi |
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| Rok vydání: | 2020 |
| Předmět: |
pump probe spectroscopy
TD-DFTB Semiclassical physics Non-equilibrium thermodynamics FOS: Physical sciences Electron 01 natural sciences electron ion dynamics purl.org/becyt/ford/1 [https] Tight binding Physics - Chemical Physics 0103 physical sciences Ultrafast laser spectroscopy purl.org/becyt/ford/1.4 [https] QC176 Physical and Theoretical Chemistry Quantum Physics Chemical Physics (physics.chem-ph) 010304 chemical physics Computational Physics (physics.comp-ph) simulation Computer Science Applications Computational physics Excited state Physics - Computational Physics Graphene nanoribbons |
| Zdroj: | CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET Journal of Chemical Theory and Computation |
| ISSN: | 1549-9626 1549-9618 |
| Popis: | The increasing need to simulate the dynamics of photoexcited molecular and nanosystems in the sub-picosecond regime demands new efficient tools able to describe the quantum nature of matter at a low computational cost. By combining the power of the approximate DFTB method with the semiclassical Ehrenfest method for nuclear-electron dynamics we have achieved a real-time time-dependent DFTB (TD-DFTB) implementation that fits such requirements. In addition to enabling the study of nuclear motion effects in photoinduced charge transfer processes, our code adds novel features to the realm of static and time-resolved computational spectroscopies. In particular, the optical properties of periodic materials such as graphene nanoribbons or the use of corrections such as the "LDA+U" and "pseudo SIC" methods to improve the optical properties in some systems, can now be handled at the TD-DFTB level. Moreover, the simulation of fully-atomistic time-resolved transient absorption spectra and impulsive vibrational spectra can now be achieved within reasonable computing time, owing to the good performance of the implementation and a parallel simulation protocol. Its application to the study of UV/visible light-induced vibrational coherences in molecules is demonstrated and opens a new door into the mechanisms of non-equilibrium ultrafast phenomena in countless materials with relevant applications. Comment: 51 pages, 7 figures, 1 TOC graphic, submitted to JCTC |
| Databáze: | OpenAIRE |
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