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

Molecular Orbital Theory II

Molecular Orbital Theory II

Molecular Orbital Energy Diagrams

Hybridization of Atomic Orbitals II

Hybridization of Atomic Orbitals II

sp3d and sp3d 2 Hybridization

Molecular Orbital Theory I

Molecular Orbital Theory I

Overview of Molecular Orbital Theory

Hybridization of Atomic Orbitals I

Hybridization of Atomic Orbitals I

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...

Valence Bond Theory and Hybridized Orbitals

Valence Bond Theory and Hybridized Orbitals

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...

Chemical Shift: Internal References and Solvent Effects

Chemical Shift: Internal References and Solvent Effects

In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...

You might also read

Related Articles

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

Sort by

Same author

The topology of the magnetically induced ring current of C<sub>13</sub>Cl<sub>2</sub>.

Chemical science·2026

Same author

One-Step Relativistic Driven Similarity Renormalization Group Multireference Perturbation Theory.

Journal of chemical theory and computation·2026

Same author

Metastable excited states of iodide-alkyl halide cluster anions: Insights from photodetachment spectroscopy and non-Hermitian quantum chemistry.

The Journal of chemical physics·2026

Same author

The Anionic States of Ubiquinone Characterized by Second-Order Approximate Coupled-Cluster Theory.

Journal of computational chemistry·2026

Same author

A Fresh Look at Signatures of <i>s</i>-Wave Scattering: Symmetry and the Breakdown of the Born-Oppenheimer Approximation.

The journal of physical chemistry. A·2026

Same author

Infrared Detection and High-Resolution Spectroscopic Study of Very Heavy Carbon Subchalcogenides: Tricarbon Telluride, C<sub>3</sub>Te, and Carbon Subtelluride, TeC<sub>3</sub>Te.

The journal of physical chemistry. A·2026

Search research articles

Related Experiment Video

Updated: Jun 13, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Analytic gradients for Mukherjee's multireference coupled-cluster method using two-configurational

Thomas-C Jagau¹, Eric Prochnow, Francesco A Evangelista

¹Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany. jagau@uni-mainz.de

The Journal of Chemical Physics

|April 22, 2010

Summary

This study presents analytic gradients for the Mahapatra-type multireference coupled-cluster method (Mk-MRCC) using two-configurational self-consistent field (TCSCF) orbitals. It highlights the impact of orbital relaxation on molecular structures for m-arynes and nitrenes.

More Related Videos

Spatial Separation of Molecular Conformers and Clusters

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

Related Experiment Videos

Last Updated: Jun 13, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

Spatial Separation of Molecular Conformers and Clusters

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

Area of Science:

Quantum Chemistry
Computational Chemistry
Theoretical Chemistry

Background:

State-specific multireference coupled-cluster (Mk-MRCC) methods are crucial for describing systems with strong static and dynamic electron correlation.
Previous implementations of Mk-MRCC gradients were limited to restricted Hartree-Fock (HF) orbitals, neglecting orbital relaxation effects.

Purpose of the Study:

To develop and implement analytic gradients for the Mk-MRCC singles and doubles (Mk-MRCC(2)) method utilizing two-configurational self-consistent field (TCSCF) orbitals.
To investigate the influence of orbital relaxation on the calculation of equilibrium geometries for challenging molecular systems.

Main Methods:

Analytic gradient calculations for the Mk-MRCC(2) method.
Incorporation of TCSCF orbitals and coupled-perturbed TCSCF (CP-TCSCF) theory to account for orbital relaxation.
Geometry optimizations of m-arynes and nitrenes.

Main Results:

Successful implementation of Mk-MRCC(2) gradients with TCSCF orbitals.
Demonstrated significant influence of orbital relaxation on computed equilibrium structures.
Comparison of results with single-reference coupled-cluster and Mk-MRCC(2) using HF orbitals.

Conclusions:

The inclusion of orbital relaxation via TCSCF orbitals in Mk-MRCC calculations is essential for accurate geometry optimizations.
The developed method provides a more robust approach for studying systems with complex electronic structures.