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

Hückel's Rule Diagram of π MOs: Frost Circle01:08

Hückel's Rule Diagram of π MOs: Frost Circle

6.3K
The Frost circle or the inscribed polygon method is a graphical method for determining the relative energies of π molecular orbitals (MOs) for planar, fully conjugated, and monocyclic compounds. This method was first described by A. A. Frost and Boris Musulin in 1953.
A Frost circle is constructed by drawing a polygon whose number of edges is equal to the number of carbons of the given cyclic system, with one of the vertices pointing down. Then, a circle is drawn enclosing the polygon so that...
6.3K
Woodward–Hoffmann Selection Rules and Microscopic Reversibility01:34

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

4.2K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
4.2K
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control01:23

Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control

4.5K
The addition of a hydrogen halide to 1,3-butadiene gives a mixture of 1,2- and 1,4-adducts. Since more substituted alkenes are more stable, the 1,4-adduct is expected to be the major product. However, the product distribution is strongly influenced by temperature; low temperature favors the 1,2-adduct, whereas the 1,4-adduct is predominant at high temperature.
4.5K
Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene01:17

Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene

9.8K
The electrophilic addition of hydrogen halides such as HBr to alkenes and nonconjugated dienes gives a single product as per Markovnikov’s rule.
9.8K
Debye–Huckel–Onsager Conductance Equation01:28

Debye–Huckel–Onsager Conductance Equation

217
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect.
217
Propagation of Action Potentials01:23

Propagation of Action Potentials

14.1K
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
14.1K

You might also read

Related Articles

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

Sort by
Same author

Measurement Contextuality and Planck's Constant.

New journal of physics·2026
Same author

Shaping chaos in bilayer graphene cavities.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

The non-disjoint ontic states of the Grassmann ontological model, transformation contextuality, and the single qubit stabilizer subtheory.

Journal of physics. A, Mathematical and theoretical·2026
Same author

Ultracold Molecular Collisions: Quasiclassical, Semiclassical, and Classical Approaches in the Quantum Regime.

Chemical reviews·2025
Same author

Polaron catastrophe within quantum acoustics.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

Direct visualization of relativistic quantum scars in graphene quantum dots.

Nature·2024
Same journal

Revisiting crossed-correlated baths in open quantum systems simulated by HEOM or T-TEDOPA.

The Journal of chemical physics·2026
Same journal

Vesicle size and membrane composition control monomer transfer pathways in multicomponent lipid vesicles.

The Journal of chemical physics·2026
Same journal

Polaron-mediated exciton dynamics of P(NDI2OD-T2) unveiled by transient absorption spectroscopy under electrochemical conditions.

The Journal of chemical physics·2026
Same journal

Green-Kubo relation in a mesoscale odd fluid model.

The Journal of chemical physics·2026
Same journal

Nitrogenation of microscopic MoS2 surfaces by oxidation scanning probe lithography.

The Journal of chemical physics·2026
Same journal

Molecular structure, binding, and disorder in TDBC-Ag plexcitonic assemblies.

The Journal of chemical physics·2026
See all related articles

Related Experiment Video

Updated: Apr 1, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
07:56

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

9.1K

Directed HK propagator.

Lucas Kocia1, Eric J Heller1

  • 1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.

The Journal of Chemical Physics
|October 3, 2015
PubMed
Summary
This summary is machine-generated.

The directed Heller-Herman-Kluk-Kay (DHK) method accurately predicts coherent state autocorrelations in quasi-periodic systems. Its simplified integral improves performance, especially with larger action gradients, suggesting broad applicability.

More Related Videos

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

9.1K
Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1
11:27

Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1

Published on: September 18, 2019

10.1K

Related Experiment Videos

Last Updated: Apr 1, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
07:56

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

9.1K
Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

9.1K
Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1
11:27

Single-Molecule Förster Resonance Energy Transfer Methods for Real-Time Investigation of the Holliday Junction Resolution by GEN1

Published on: September 18, 2019

10.1K

Area of Science:

  • Quantum mechanics
  • Computational chemistry
  • Theoretical physics

Background:

  • The Heller-Herman-Kluk-Kay (HHK) method is a powerful tool for simulating quantum systems.
  • Traditional HHK methods involve computationally expensive high-dimensional integrals.
  • A simplified "directed" version, DHK, has shown promise but lacked formal justification.

Purpose of the Study:

  • To provide a formal justification for the success of the directed Heller-Herman-Kluk-Kay (DHK) time propagator.
  • To examine DHK's performance in one-dimensional bound systems with quasi-periodic motion.
  • To understand the conditions under which DHK accurately captures coherent state autocorrelations.

Main Methods:

  • Investigated DHK's performance on one-dimensional bound systems exhibiting quasi-periodic motion.
  • Focused on the simplification offered by DHK's single one-dimensional integral compared to the full HHK's 2N-dimensional integral.
  • Numerically examined DHK's accuracy using a one-dimensional quartic oscillator.

Main Results:

  • DHK accurately captures coherent state autocorrelations when its integral aligns with the fastest growing manifold and avoids being perpendicular to the action gradient.
  • Performance of DHK improves with larger action gradients.
  • Numerical simulations on a quartic oscillator confirmed that these conditions are frequently met, leading to good performance.

Conclusions:

  • The study provides a formal explanation for the effectiveness of the DHK time propagator.
  • DHK's accuracy is linked to specific alignments of its integral with system dynamics.
  • The findings suggest DHK may be applicable to systems with significant anharmonicity.