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

Crystal Field Theory - Tetrahedral and Square Planar Complexes02:46

Crystal Field Theory - Tetrahedral and Square Planar Complexes

48.1K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
48.1K
Electronic Structure of Atoms02:28

Electronic Structure of Atoms

27.9K

An atom comprises protons and neutrons, which are contained inside the dense, central core called the nucleus, with electrons present around the nucleus. Taking into account the wave–particle duality of electrons and the uncertainty in position around the nucleus, quantum mechanics provides a more accurate model for the atomic structure. It describes atomic orbitals as the regions around the nucleus where electrons of discrete energy exist, characterized by four quantum...
27.9K
Crystal Field Theory - Octahedral Complexes02:58

Crystal Field Theory - Octahedral Complexes

30.6K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.6K
π Electron Effects on Chemical Shift: Overview01:27

π Electron Effects on Chemical Shift: Overview

1.6K
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,...
1.6K
Predicting Molecular Geometry02:27

Predicting Molecular Geometry

44.7K
VSEPR Theory for Determination of Electron Pair Geometries
44.7K
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds01:14

π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

1.8K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.8K

You might also read

Related Articles

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

Sort by
Same author

The x-ray absorption spectrum of the propargyl radical C3H3●.

The Journal of chemical physics·2026
Same author

Probing the Ultrafast Photodynamics of Dihydroazulene with In Silico Time-Resolved Photoelectron Spectroscopy and Ultrafast Electron Diffraction.

The journal of physical chemistry. A·2026
Same author

Oriented Electric Field-Driven Cis-Azobenzene Selective Diborylation Reaction at the Single-Molecule Level.

Journal of the American Chemical Society·2026
Same author

Twisting Rhodamine─Design of Bright Dyes for Circularly Polarized Fluorescence.

Journal of the American Chemical Society·2026
Same author

Reduced Density Matrix and Cumulant Approximations of Quantum Linear Response.

Journal of chemical theory and computation·2026
Same author

[11]Cycloparaphenylene incorporating a redox-active dithiafulvene moiety provides access to a carbon nanohoop with an unpaired electron along the core.

Chemical communications (Cambridge, England)·2026
Same journal

Kinetic and Mechanistic Insights into H-Abstraction and Subsequent Isomerization and Decomposition of Monoglyme and Key Combustion Intermediates.

The journal of physical chemistry. A·2026
Same journal

First-Principles Analysis of Protonation-Induced Electronic Effects in Tetrakis(<i>p</i>-aminophenyl)porphyrin (TAPP).

The journal of physical chemistry. A·2026
Same journal

Exploring the Reactivity of the CH Radical toward Nitrous Oxide in the Context of the Interstellar Medium.

The journal of physical chemistry. A·2026
Same journal

Infrared Photodissociation Spectroscopy of Benzene-V<sup>+</sup>(CO)<sub>n</sub> "Piano Stool" Cations.

The journal of physical chemistry. A·2026
Same journal

Correction to "Solvent-Dependent Ultrafast Photochemical Dynamics of <i>N</i>-Methyl Oxindole Overcrowded Alkene Molecular Motors".

The journal of physical chemistry. A·2026
Same journal

Accelerating the Discovery of Superhalogens via Physics-Informed Graph Neural Networks.

The journal of physical chemistry. A·2026
See all related articles

Related Experiment Video

Updated: Jan 14, 2026

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

8.7K

Penguin: A Python-Based Program for Electronic Structure Calculations Based on Coupled Cluster Theory.

Andreas Erbs Hillers-Bendtsen1,2, Magnus Bukhave Johansen1, Theo Juncker von Buchwald1,3

  • 1Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK 2100 Copenhagen, Denmark.

The Journal of Physical Chemistry. A
|October 27, 2025
PubMed
Summary
This summary is machine-generated.

Penguin is a new open-source Python program for molecular property and spectroscopy calculations. It introduces open-source cluster perturbation theory and supports interactive use for education and research.

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

8.9K
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

8.0K

Related Experiment Videos

Last Updated: Jan 14, 2026

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

8.7K
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

8.9K
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

8.0K

Area of Science:

  • Computational chemistry
  • Quantum chemistry
  • Molecular modeling

Background:

  • Coupled cluster (CC) theory and perturbation theory (PT) are essential for accurate molecular property and spectroscopy calculations.
  • Existing open-source software often lacks comprehensive implementations of advanced PT methods, limiting accessibility for research and education.
  • The development of user-friendly and efficient computational tools is crucial for advancing theoretical chemistry.

Purpose of the Study:

  • To introduce the Penguin program, an open-source software package for molecular property and spectroscopy calculations.
  • To provide the first open-source implementation of cluster perturbation theory (CPT) approaches.
  • To facilitate the rapid prototyping and development of novel CC and PT methods.

Main Methods:

  • The Penguin program is implemented in Python using a modular and object-oriented design.
  • It incorporates a matrix element library for efficient evaluation of terms in coupled cluster theory.
  • The software supports interactive usage via Jupyter notebooks and includes an OpenMP/MPI parallel version of the CC2 model.

Main Results:

  • Penguin enables molecular property and spectroscopy calculations using coupled cluster and perturbation theory.
  • It offers the first open-source implementation of cluster perturbation theory.
  • The program demonstrates high-performance computing potential through its parallelized CC2 model.

Conclusions:

  • The Penguin program provides a valuable, open-source resource for computational chemists.
  • Its features support both educational purposes and the advancement of theoretical chemistry methods.
  • The software's design facilitates efficient and accessible molecular property and spectroscopy calculations.