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

MO Theory and Covalent Bonding02:40

MO Theory and Covalent Bonding

The molecular orbital theory describes the distribution of electrons in molecules in a manner similar to the distribution of electrons in atomic orbitals. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital. Mathematically, the linear combination of atomic orbitals (LCAO) generates molecular orbitals. Combinations of in-phase atomic orbital wave functions result in regions with a high probability of electron density, while...
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,...
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,...
Molecular Orbital Theory I02:35

Molecular Orbital Theory I

Overview of Molecular Orbital Theory
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation04:01

Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation

Thus far, the ideal gas law, PV = nRT, has been applied to a variety of different types of problems, ranging from reaction stoichiometry and empirical and molecular formula problems to determining the density and molar mass of a gas. However, the behavior of a gas is often non-ideal, meaning that the observed relationships between its pressure, volume, and temperature are not accurately described by the gas laws.

You might also read

Related Articles

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

Sort by
Same author

A Mitochondria-Targeting Probe for Extended Imaging of H<sub>2</sub>S and Viscosity in Rheumatoid Arthritis.

Analytical chemistry·2026
Same author

The Effect of Aza-Glycine Substitution on the Internalization of Dabcyl-Containing Short Oligoarginine.

Biomedicines·2026
Same author

Theoretical Study of 1s, 2s, and 2p Core Electron Binding Energies of Third-Period Elements Calculated by the ΔSCF Method, Koopmans' Theorem, and Slater's Transition State Theory within the Framework of Hartree-Fock and Kohn-Sham Theory.

The journal of physical chemistry. A·2025
Same author

Validation of Long-Range-Corrected LC2gau Functional for Koopmans' Prediction of Core and Valence Ionization Energies with Diverse Data.

The journal of physical chemistry. A·2025
Same author

Comprehensive Insights into Exciplex Behavior in Nonpolar Media: Revisiting Weller's Framework with Molecular Conformation.

The journal of physical chemistry. A·2025
Same author

Spontaneous detection of F<sup>-</sup> and viscosity using a multifunctional tetraphenylethene-lepidine probe: Exploring environmental applications.

Food chemistry·2024

Related Experiment Video

Updated: Jun 7, 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 Koopmans' theorem in density functional theory.

Takao Tsuneda1, Jong-Won Song, Satoshi Suzuki

  • 1Advanced Science Institute, RIKEN, Wako, Saitama 351-0198, Japan. tsuneda@riken.jp

The Journal of Chemical Physics
|November 9, 2010
PubMed
Summary
This summary is machine-generated.

Long-range corrected (LC) density functional theory accurately predicts orbital energies. This accuracy stems from LC functionals maintaining constant orbital energies for fractional occupations, unlike other methods.

More Related Videos

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
12:11

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
13:56

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Related Experiment Videos

Last Updated: Jun 7, 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

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
12:11

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
13:56

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations

Published on: October 12, 2019

Area of Science:

  • Computational Chemistry
  • Quantum Chemistry
  • Materials Science

Background:

  • Density functional theory (DFT) is a cornerstone of modern computational chemistry.
  • Accurate prediction of electronic properties, such as ionization potentials and electron affinities, is crucial for understanding molecular behavior.
  • Existing DFT functionals often struggle to quantitatively reproduce experimental values for these properties.

Purpose of the Study:

  • To elucidate the reasons behind the quantitative accuracy of long-range corrected (LC) density functional theory in predicting orbital energies.
  • To investigate the relationship between orbital energies and fundamental electronic properties like vertical ionization potentials (IPs) and electron affinities (EAs).
  • To identify the specific characteristics of LC functionals responsible for their improved performance.

Main Methods:

  • Comparison of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies from LC-DFT with experimental IPs and EAs for various molecules.
  • Analysis of the impact of the short-range component of LC functionals on orbital energy reproducibility.
  • Fractional occupation calculations to examine the stability of orbital energies with respect to electron number changes.

Main Results:

  • LC exchange functionals yield orbital energies that closely match minus vertical IPs and EAs, while other functionals significantly underestimate them.
  • The short-range characteristics of LC functionals have minimal impact on the reproducibility of orbital energies.
  • LC functionals uniquely maintain orbital energies nearly constant for fractional occupations, a behavior attributed to the cancellation of exchange and Coulomb self-interaction energies.

Conclusions:

  • The quantitative accuracy of LC-DFT for orbital energies arises from their ability to stabilize orbital energies across fractional occupations.
  • This stabilization is a direct consequence of the cancellation between exchange self-interaction (via potential derivatives) and Coulomb self-interaction energies, observed in LC functionals for most atoms and molecules.
  • LC-DFT provides a more reliable framework for predicting electronic properties compared to conventional DFT methods.