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

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
Van der Waals Equation01:10

Van der Waals Equation

The ideal gas law is an approximation that works well at high temperatures and low pressures. The van der Waals equation of state (named after the Dutch physicist Johannes van der Waals, 1837−1923) improves it by considering two factors.
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
Debye–Huckel–Onsager Conductance Equation01:28

Debye–Huckel–Onsager Conductance Equation

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. According to this equation,...
The Van der Waals Equation01:26

The Van der Waals Equation

The ideal gas law is based on two simplifying assumptions: first, that there are no intermolecular attractions between gas molecules, and second, that the volume occupied by the molecules themselves is negligible compared with the volume of the container. However, these assumptions don't hold up under all conditions - specifically, at high pressures and low temperatures, as gas tends to deviate from ideal gas behavior.The van der Waals equation is an enhanced version of the ideal gas law,...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...

You might also read

Related Articles

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

Sort by
Same author

Predicting unknown binding sites for transition-metal-based compounds in proteins.

PloS one·2026
Same author

Electronic and Optical Properties of Paracyclophanes.

Chimia·2026
Same author

Zero-shot design of a <i>de novo</i> metalloenzyme.

bioRxiv : the preprint server for biology·2026
Same author

A pictorial (and hopefully pedagogical) discussion on the Born-Oppenheimer approximation.

Foundations of chemistry·2026
Same author

A molecule with half-Möbius topology.

Science (New York, N.Y.)·2026
Same author

Atom-centered electric multipole moments dynamically generated from QM/MM MD simulations.

The Journal of chemical physics·2026

Related Experiment Video

Updated: Jun 18, 2026

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

On nonadiabatic coupling vectors in time-dependent density functional theory.

Ivano Tavernelli, Basile F E Curchod, Ursula Rothlisberger

    The Journal of Chemical Physics
    |November 26, 2009
    PubMed
    Summary
    This summary is machine-generated.

    This study confirms the rigorous calculation of nonadiabatic coupling vectors within time-dependent density functional theory (TDDFT). The developed method is shown to be equivalent to existing approaches, enhancing computational chemistry research.

    More Related Videos

    Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
    08:22

    Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

    Published on: August 6, 2018

    Related Experiment Videos

    Last Updated: Jun 18, 2026

    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

    Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
    08:22

    Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization

    Published on: August 6, 2018

    Area of Science:

    • Quantum Chemistry
    • Computational Physics
    • Theoretical Chemistry

    Background:

    • Time-dependent density functional theory (TDDFT) is a powerful method for studying electronic dynamics.
    • Calculating nonadiabatic coupling vectors is crucial for understanding nonadiabatic processes in molecules.
    • Previous methods for calculating these vectors have varying levels of rigor and applicability.

    Discussion:

    • This note rigorously validates the TDDFT framework for nonadiabatic coupling vector calculations.
    • It demonstrates the full equivalence between the authors' formulation and Sugino and co-workers' approach.
    • The discussion highlights specific applications, underscoring the practical utility of the validated method.

    Key Insights:

    • The TDDFT-based method for nonadiabatic coupling vectors is mathematically sound and reliable.
    • The equivalence established simplifies theoretical comparisons and method selection.
    • Validated computational tools are essential for advancing the study of chemical dynamics.

    Outlook:

    • Further applications of this validated method will likely emerge in various areas of chemical physics.
    • This work provides a robust foundation for future developments in quantum dynamics simulations.
    • The established equivalence aids in the broader adoption and refinement of TDDFT for complex systems.