Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Adiabatic Processes for an Ideal Gas01:18

Adiabatic Processes for an Ideal Gas

4.3K
When an ideal gas is compressed adiabatically, that is, without adding heat, work is done on it, and its temperature increases. In an adiabatic expansion, the gas does work, and its temperature drops. Adiabatic compressions actually occur in the cylinders of a car, where the compressions of the gas-air mixture take place so quickly that there is no time for the mixture to exchange heat with its environment. Nevertheless, because work is done on the mixture during the compression, its...
4.3K
Pressure and Volume in an Adiabatic Process01:27

Pressure and Volume in an Adiabatic Process

3.6K
Free expansion of a gas is an adiabatic process. However, there are few differences between free expansion and adiabatic expansion. During free expansion, no work is done, and there is no change in internal energy. But, for an adiabatic expansion, work is done, and there is a change in internal energy. During an adiabatic process, the relation between the pressure and volume is obtained from the condition for the adiabatic process, that is,
3.6K
Bernoulli's Equation for Flow Along a Streamline01:30

Bernoulli's Equation for Flow Along a Streamline

1.6K
Bernoulli's equation relates the energy conservation in a fluid moving along a streamline. The equation applies to incompressible and inviscid fluids under steady flow. For such a flow, Newton's second law is applied to a small fluid element, which experiences forces due to pressure differences, gravity, and velocity variations. The force balance leads to the following form of Bernoulli's equation:
1.6K
Phase Transitions01:21

Phase Transitions

33
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
33
Phase Transitions02:31

Phase Transitions

23.6K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
23.6K
Phase Transitions: Sublimation and Deposition02:33

Phase Transitions: Sublimation and Deposition

20.6K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
20.6K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Molecular dynamics simulations for enzymatic hydride-transfer reactions: Defining environmental reaction coordinates to capture transition state diversity.

The Journal of chemical physics·2025
Same author

Reflections on Zwanzig's theories of dielectric friction.

The Journal of chemical physics·2024
Same author

Signature of Attochemical Quantum Interference upon Ionization and Excitation of an Electronic Wave Packet in Fluorobenzene.

Physical review letters·2024
Same author

Water dynamics and sum-frequency generation spectra at electrode/aqueous electrolyte interfaces.

Faraday discussions·2023
Same author

Ultrafast Rotational and Translational Energy Relaxation in Neat Liquids.

The journal of physical chemistry. B·2021
Same author

Electron Flow Characterization of Charge Transfer for Carbonic Acid to Strong Base Proton Transfer in Aqueous Solution.

The journal of physical chemistry. B·2021

Related Experiment Video

Updated: Mar 11, 2026

Evolution of Staircase Structures in Diffusive Convection
07:28

Evolution of Staircase Structures in Diffusive Convection

Published on: September 5, 2018

6.9K

Non-adiabatic transition probability dependence on conical intersection topography.

João Pedro Malhado1, James T Hynes2

  • 1Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom.

The Journal of Chemical Physics
|November 24, 2016
PubMed
Summary
This summary is machine-generated.

This study presents an analytical model for non-adiabatic transition probability at conical intersections (CIs). It finds no intrinsic difference between peaked and sloped CIs, challenging common views on non-adiabatic decay.

More Related Videos

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
06:26

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

Published on: May 15, 2017

7.7K
Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
11:51

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions

Published on: February 22, 2018

9.2K

Related Experiment Videos

Last Updated: Mar 11, 2026

Evolution of Staircase Structures in Diffusive Convection
07:28

Evolution of Staircase Structures in Diffusive Convection

Published on: September 5, 2018

6.9K
Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
06:26

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

Published on: May 15, 2017

7.7K
Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
11:51

Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions

Published on: February 22, 2018

9.2K

Area of Science:

  • Quantum Chemistry
  • Chemical Dynamics
  • Theoretical Chemistry

Background:

  • Non-adiabatic transitions are crucial in chemical reactions and molecular dynamics.
  • Conical intersections (CIs) are key regions where these transitions occur.
  • Understanding transition probabilities at CIs is essential for predicting reaction outcomes.

Purpose of the Study:

  • To derive a closed-form analytical expression for non-adiabatic transition probability at a generic conical intersection.
  • To investigate how topographical features of conical intersections influence transition probabilities.
  • To compare the efficiency of peaked versus sloped CIs in promoting non-adiabatic decay.

Main Methods:

  • Derivation of an analytical expression based on the Landau-Zener model for a distribution of trajectories.
  • Analysis of the transition probability's dependence on CI topography and approach dynamics.
  • Comparison of theoretical predictions with surface hopping simulation results.

Main Results:

  • A closed-form analytical expression for non-adiabatic transition probability at CIs was derived.
  • No intrinsic difference in non-adiabatic decay efficiency was found between peaked and sloped CIs at the same crossing velocity.
  • Transition probability depends on the direction of approach and can be influenced by reduced mass effects on CI topography.

Conclusions:

  • The efficiency of non-adiabatic decay at CIs is primarily governed by dynamical effects, not solely by topographical features.
  • Common assumptions about the superior efficiency of peaked CIs are challenged by this finding.
  • The derived analytical model provides a valuable tool for understanding and predicting non-adiabatic dynamics in molecular systems.