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

The Quantum-Mechanical Model of an Atom02:45

The Quantum-Mechanical Model of an Atom

42.4K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
42.4K
The Uncertainty Principle04:08

The Uncertainty Principle

23.4K
Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He...
23.4K
π Electron Effects on Chemical Shift: Overview01:27

π Electron Effects on Chemical Shift: Overview

1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
The Energies of Atomic Orbitals03:21

The Energies of Atomic Orbitals

24.0K
In an atom, the negatively charged electrons are attracted to the positively charged nucleus. In a multielectron atom, electron-electron repulsions are also observed. The attractive and repulsive forces are dependent on the distance between the particles, as well as the sign and magnitude of the charges on the individual particles. When the charges on the particles are opposite, they attract each other. If both particles have the same charge, they repel each other.
24.0K
Free Energy Changes for Nonstandard States03:25

Free Energy Changes for Nonstandard States

11.4K
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
 
where R is the gas constant (8.314 J/K·mol), T is the absolute temperature in kelvin, and Q is the reaction quotient. This equation may be used to predict the spontaneity of a process under any given set of conditions.
Reaction Quotient...
11.4K
Entropy and Solvation02:05

Entropy and Solvation

7.1K
The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ...
7.1K

You might also read

Related Articles

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

Sort by
Same author

Machine Learning-Enhanced Orbital-Free Density Functional Theory.

Journal of chemical theory and computation·2026
Same author

Learning the One-Electron Reduced Density Matrix at SCF Convergence Thresholds.

Journal of chemical theory and computation·2025
Same author

Density-Functionalized QM/MM Delivers Chemical Accuracy For Solvated Systems.

Journal of chemical theory and computation·2025
Same author

The Analysis of Electron Densities: From Basics to Emergent Applications.

Chemical reviews·2024
Same author

Nonadiabatic molecular dynamics with subsystem density functional theory: application to crystalline pentacene.

Journal of physics. Condensed matter : an Institute of Physics journal·2024
Same author

"Atomic Topping" of MnO<sub></sub> on Al<sub>2</sub>O<sub>3</sub> to Create Electron-Rich, Aperiodic, Lattice Oxygens that Resemble Noble Metals for Catalytic Oxidation.

Journal of the American Chemical Society·2024

Related Experiment Video

Updated: Jul 11, 2025

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

8.2K

Entropy is a good approximation to the electronic (static) correlation energy.

Jessica A Martinez B1, Xuecheng Shao1,2, Kaili Jiang1

  • 1Department of Chemistry, Rutgers University, Newark, New Jersey 07102, USA.

The Journal of Chemical Physics
|November 15, 2023
PubMed
Summary

Entropy calculations offer a novel approximation for electronic correlation energy in quantum chemistry. This method, using orbital occupation numbers, provides a computationally efficient way to understand electron interactions in chemical systems.

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

8.5K
Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene
08:44

Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene

Published on: August 22, 2017

7.8K

Related Experiment Videos

Last Updated: Jul 11, 2025

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

8.2K
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

8.5K
Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene
08:44

Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene

Published on: August 22, 2017

7.8K

Area of Science:

  • Quantum Chemistry
  • Computational Physics
  • Electronic Structure Theory

Background:

  • Electronic correlation energy is crucial for accurate molecular simulations.
  • Current methods for calculating correlation energy can be computationally intensive.
  • Entropy-based measures offer a potential alternative for approximating correlation energy.

Purpose of the Study:

  • To provide formal evidence and computational support for using entropy as an approximation to electronic correlation energy.
  • To establish a theoretical foundation for entropy-based methods in electronic structure calculations.

Main Methods:

  • Utilizing mean field methods and distributions of orbital occupation numbers.
  • Assuming correlation energy is a functional of occupation numbers derived from an invertible distribution.
  • Performing pilot calculations using Fermi-Dirac, Gaussian, and linear occupation number distributions.

Main Results:

  • Formal evidence supports the hypothesis that -σS (where S is entropy) approximates correlation energy.
  • Computational results verify this hypothesis across various mean field methods and occupation distributions.
  • The approach is validated for systems involving bond breaking and chemical reactions.

Conclusions:

  • Entropy of orbital occupation number distributions serves as a good approximation for electronic correlation energy.
  • This work provides a formal basis for methods like i-DMFT and TAO-DFT.
  • The findings pave the way for broader application of entropy functionals in approximating static electronic correlation.