Ultrafast Molecular Dynamics
Ultrafast Molecular Dynamics - Related Videos
10:52
Direct Imaging of Laser-driven Ultrafast Molecular Rotation
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Cited by 5 •
2017
We present a protocol for creating a real-time movie of a molecular rotational wave packet using a high-resolution Coulomb explosion imaging setup.
13:58
Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics
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Cited by 1 •
2016
This paper reports the nanomaterial fabrication of a fullerene Si substrate inspected and verified by nanomeasurements and molecular dynamic simulation.
10:37
Spatial Separation of Molecular Conformers and Clusters
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Cited by 3 •
2014
We present a technique that allows the spatial separation of different conformers or clusters present in a molecular beam. An electrostatic deflector is used to separate species by their mass-to-dipole moment ratio, leading to the production of gas-phase ensembles of a single conformer or cluster stoichiometry.
06:37
Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
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Cited by 2 •
2021
Melts and fluids are ubiquitous vectors of mass transport in natural systems. We have developed an open-source package to analyze ab initio molecular-dynamics simulations of such systems. We compute structural (bonding, clusterization, chemical speciation), transport (diffusion, viscosity) and thermodynamic properties (vibrational spectrum).
05:57
Blood Flow Imaging with Ultrafast Doppler
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Cited by 10 •
2020
This protocol shows how to apply ultrafast ultrasound Doppler imaging to quantify blood flows. After a 1 s long acquisition, the experimenter has access to a movie of the full field of view with axial velocity values for each pixel every ≈0.3 ms (depending on the ultrasound time of flight).
FAQs
The pump pulse places molecules in an excited electronic state, and a delayed probe pulse samples how that state changes. Researchers record transient absorption or emission at different delays, then relate evolving signals to energy redistribution, bond reorganization, or loss of excitation. This time-dependent comparison provides evidence for structural and electronic changes that a single, averaged measurement would conceal.
Nonradiative decay transfers an excited molecule to another state without emitting light, while energy redistribution moves excitation through the molecule or between relevant motions. Their signatures help distinguish how an initially excited system evolves before a chemical transformation is complete. Tracking these processes clarifies whether observed changes reflect electronic relaxation, bond rearrangement, or pathways leading toward reaction.
Computational simulations connect measured spectroscopic signals with atomic motion and possible reaction pathways. A transient absorption or emission feature alone does not directly identify which structural change produced it. Comparing experimental time-dependent signals with simulated molecular behavior helps assign the observed dynamics to energy flow, bond reorganization, electron or proton transfer, or other chemically relevant events.
A typical workflow uses an ultrashort laser pulse to excite the molecule, followed by probe pulses delivered at controlled time delays. Researchers measure transient absorption or emission across those delays to build a time-dependent record of the excited system. They then interpret the changing signals alongside computational simulations, linking spectroscopic evolution to atomic motion and reaction pathways.
The approach can identify how energy moves through a molecule, how bonds reorganize, and how excited states undergo nonradiative decay. It also helps follow electron and proton transfer and bond breaking as these events develop. By connecting these changes with reaction pathways, researchers gain mechanistic information rather than only observing the starting and final molecular states.
Ultrafast molecular dynamics supports studies of photochemical reactions, molecular photophysics, catalysis, solar-energy conversion, and materials chemistry. Its value comes from resolving the early molecular events that govern later chemical behavior. In these areas, measurements combined with simulations can show how excitation, energy flow, charge-related transfer, and structural change contribute to useful function or reactivity.