Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Covalent Bonds

Covalent Bonds

Covalent Bonds

Covalent Bonds

Overview
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally,...

Covalent Bonding and Lewis Structures

Covalent Bonding and Lewis Structures

Compared to ionic bonds, which results from the transfer of electrons between metallic and nonmetallic atoms, covalent bonds result from the mutual attraction of atoms for a “shared” pair of electrons.

Polar Covalent Bonds

Polar Covalent Bonds

Covalent bonds are formed between two atoms when both have similar tendencies to attract electrons to themselves (i.e., when both atoms have identical or fairly similar ionization energies and electron affinities). Nonmetal atoms frequently form covalent bonds with other nonmetal atoms. For example, the hydrogen molecule, H2, contains a covalent bond between its two hydrogen atoms. When two separate hydrogen atoms with a particular potential energy approach each other, their valence orbitals...

MO Theory and Covalent Bonding

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...

Network Covalent Solids

Network Covalent Solids

Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...

You might also read

Related Articles

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

Sort by

Same author

Metal-regulated MXene nanozyme with second near-infrared-triggered photothermal and chemodynamic synergy for anti-infection therapy and transcriptomic deciphering of antibacterial mechanisms.

Journal of colloid and interface science·2026

Same author

A New Family of Seniority-Restricted Coupled Cluster Methods.

The journal of physical chemistry. A·2026

Same author

Ubiquitous Negative Electron Densities Discredit Smooth Energy Interpolation in Density Functional Theory.

The journal of physical chemistry letters·2026

Same author

Revisiting the Maximum Hardness Principle: A Quantitative Analysis on Reaction Datasets.

Journal of computational chemistry·2026

Same author

Topological regions and experimental carcinogenicity data of polycyclic aromatic hydrocarbons: a comprehensive resource for prediction models.

BMC research notes·2026

Same author

Seniority-zero linear canonical transformation theory.

The Journal of chemical physics·2026

Search research articles

Related Experiment Video

Updated: Feb 7, 2026

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy

Published on: March 16, 2020

SCI: a robust and reliable density-based descriptor to determine multiple covalent bond orders.

Ying Huang¹, Lianghong Liu², Chunying Rong³

¹School of Pharmacy, Hunan University of Chinese Medicine, Changsha, 410208, Hunan, China.

Journal of Molecular Modeling

|July 23, 2018

Summary

This summary is machine-generated.

This study confirms the Pauli energy

Keywords:

Density-based descriptor Multiple covalent bond Pauli energy Quintuple bond Strong covalent interaction

More Related Videos

Covalent Labeling with Diethylpyrocarbonate for Studying Protein Higher-Order Structure by Mass Spectrometry

Covalent Labeling with Diethylpyrocarbonate for Studying Protein Higher-Order Structure by Mass Spectrometry

Published on: June 15, 2021

Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI

Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI

Published on: April 18, 2011

Related Experiment Videos

Last Updated: Feb 7, 2026

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy

Published on: March 16, 2020

Covalent Labeling with Diethylpyrocarbonate for Studying Protein Higher-Order Structure by Mass Spectrometry

Covalent Labeling with Diethylpyrocarbonate for Studying Protein Higher-Order Structure by Mass Spectrometry

Published on: June 15, 2021

Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI

Methods to Quantify Pharmacologically Induced Alterations in Motor Function in Human Incomplete SCI

Published on: April 18, 2011

Area of Science:

Quantum chemistry
Chemical bonding theory

Background:

Strong covalent interactions (SCI) with bond orders >= 2 were previously identified using Pauli energy.
The signature isosurface shapes for double, triple, and quadruple bonds were established as dumbbell, donut, and four-beats, respectively.

Purpose of the Study:

To systematically investigate the influence of methodologies and basis sets on SCI signature isosurface shapes.
To demonstrate the robustness of the SCI index in determining multiple covalent bond orders.
To differentiate between bond strength and bond order, particularly in transition metal systems.

Main Methods:

Analysis of Pauli energy and signature isosurface shapes.
Systematic investigation of different computational methodologies and basis sets.
Case study using molybdenum dimer in various environments (vacuum, molecular sandwich, C80 cage).

Main Results:

The SCI signature isosurface shapes are robust across different computational methods and basis sets.
Bond strength and bond order are distinct concepts, especially for transition metals where short bond lengths do not always imply higher bond orders.
The SCI index is confirmed as a reliable descriptor for multiple covalent bond orders.

Conclusions:

The Pauli energy-based SCI index accurately determines multiple covalent bond orders.
The methodology is robust and applicable to various chemical systems, including transition metals.
The study clarifies the relationship between bond length, bond strength, and bond order.