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

Molecular Orbital Theory I02:35

Molecular Orbital Theory I

37.0K
Overview of Molecular Orbital Theory
37.0K
Hybridization of Atomic Orbitals II03:35

Hybridization of Atomic Orbitals II

37.6K
sp3d and sp3d 2 Hybridization
37.6K
Hybridization of Atomic Orbitals I03:24

Hybridization of Atomic Orbitals I

53.8K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
53.8K
Molecular Orbital Theory II03:51

Molecular Orbital Theory II

22.2K
Molecular Orbital Energy Diagrams
22.2K
Atomic Orbitals02:44

Atomic Orbitals

39.9K
An atomic orbital represents the three-dimensional regions in an atom where an electron has the highest probability to reside. The radial distribution function indicates the total probability of finding an electron within the thin shell at a distance r from the nucleus. The atomic orbitals have distinct shapes which are determined by l, the angular momentum quantum number. The orbitals are often drawn with a boundary surface, enclosing densest regions of the cloud.
39.9K
Valence Bond Theory and Hybridized Orbitals02:38

Valence Bond Theory and Hybridized Orbitals

24.5K
According to valence bond theory, a covalent bond results when: (1) an orbital on one atom overlaps an orbital on a second atom, and (2) the single electrons in each orbital combine to form an electron pair. The strength of a covalent bond depends on the extent of overlap of the orbitals involved. Maximum overlap is possible when the orbitals overlap on a direct line between the two nuclei.
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
24.5K

You might also read

Related Articles

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

Sort by
Same author

An Algebraic-Diagrammatic Construction for Vertex Corrections to the <i>GW</i> Self-Energy.

The journal of physical chemistry letters·2026
Same author

Connection between <i>GW</i> and Extended Coupled Cluster.

Journal of chemical theory and computation·2026
Same author

Reference Energies for Non-Relativistic Core Ionization Potentials.

Journal of chemical theory and computation·2026
Same author

The Newton-X platform for mixed quantum-classical dynamics.

Physical chemistry chemical physics : PCCP·2026
Same author

Pediatric Robotic Cochlear Implantation: Hearing Outcomes.

Audiology & neuro-otology·2026
Same author

Social media users experience more political hostility in less economically equal and less democratic societies.

Nature human behaviour·2026

Related Experiment Video

Updated: Oct 26, 2025

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

8.6K

Excited States from State-Specific Orbital-Optimized Pair Coupled Cluster.

Fábris Kossoski1, Antoine Marie1, Anthony Scemama1

  • 1Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France.

Journal of Chemical Theory and Computation
|July 26, 2021
PubMed
Summary

The pair coupled cluster doubles (pCCD) method offers accurate excited-state energies comparable to DOCI when using state-specific orbitals. A new Δoo-pCCD model also accurately targets doubly excited states with lower computational cost.

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

8.4K
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
05:51

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method

Published on: July 19, 2019

6.4K

Related Experiment Videos

Last Updated: Oct 26, 2025

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

8.6K
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

8.4K
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
05:51

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method

Published on: July 19, 2019

6.4K

Area of Science:

  • Quantum Chemistry
  • Computational Chemistry
  • Electronic Structure Theory

Background:

  • The pair coupled cluster doubles (pCCD) method approximates electron correlation with polynomial cost, unlike the exponential cost of doubly occupied configuration interaction (DOCI).
  • Previous studies show pCCD yields accurate ground-state energies close to DOCI.
  • The applicability of pCCD to excited states and its comparison with DOCI remained an open question.

Purpose of the Study:

  • To investigate the accuracy of pCCD for excited-state energies.
  • To compare pCCD and DOCI excited-state energies, particularly concerning orbital choices.
  • To develop and assess a direct pCCD-based method for targeting doubly excited states.

Main Methods:

  • Symmetric dissociation of the linear H4 molecule was explored to analyze excited states.
  • Calculations were performed using both standard pCCD with Hartree-Fock orbitals and optimized orbitals at the pCCD level (oo-pCCD).
  • A novel Δoo-pCCD model was introduced to calculate excitation energies directly from energy differences between ground and excited states.

Main Results:

  • pCCD and DOCI excited-state energies showed significant discrepancies when using standard Hartree-Fock orbitals.
  • Employing state-specific optimized orbitals (oo-pCCD) drastically reduced the differences between pCCD and DOCI excited-state energies.
  • The Δoo-pCCD model yielded highly accurate excitation energies for doubly excited states, outperforming or matching higher-cost methods like CC3 and EOM-CCSDT.

Conclusions:

  • pCCD can provide accurate excited-state energies comparable to DOCI, provided that state-specific orbitals are utilized.
  • The developed Δoo-pCCD method offers a computationally efficient and accurate alternative for calculating doubly excited states.
  • These findings highlight the potential of pCCD-based methods for reliable and cost-effective electronic structure calculations of excited states.