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

Deactivation Processes: Jablonski Diagram01:25

Deactivation Processes: Jablonski Diagram

982
Luminescence, the emission of light by a substance that has absorbed energy, is a process that involves the interaction of molecules with light. The energy-level diagram, or Jablonski diagram, is a graphical representation of these interactions, illustrating the various states and transitions a molecule can undergo. In a typical Jablonski diagram, the lowest horizontal line represents the ground-state energy of the molecule, which is usually a singlet state. This state represents the energies...
982
Calculating Standard Free Energy Changes02:49

Calculating Standard Free Energy Changes

22.7K
The free energy change for a reaction that occurs under the standard conditions of 1 bar pressure and at 298 K is called the standard free energy change. Since free energy is a state function, its value depends only on the conditions of the initial and final states of the system. A convenient and common approach to the calculation of free energy changes for physical and chemical reactions is by use of widely available compilations of standard state thermodynamic data. One method involves the...
22.7K
Free Energy Changes for Nonstandard States03:25

Free Energy Changes for Nonstandard States

11.8K
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...
11.8K
¹H NMR: Complex Splitting01:13

¹H NMR: Complex Splitting

1.4K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.4K
The Bohr Model02:18

The Bohr Model

72.7K
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as...
72.7K
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule

1.5K
In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the...
1.5K

You might also read

Related Articles

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

Sort by
Same author

Scalable and Physics-Informed Multireference Implementation with Spin-Orbit Couplings via Modern HPC Clusters.

The journal of physical chemistry letters·2026
Same author

Concurrent Optimization of Device Architecture, Transport Layers, and Active Layer for Organic Photovoltaics by Machine Learning.

The journal of physical chemistry letters·2026
Same author

The Time-Dependent Density Matrix Renormalization Group Method for Nonadiabatic Dynamics and Electronic Dynamics.

Journal of chemical theory and computation·2026
Same author

Navigating high-dimensional processing parameters in organic photovoltaics via a multitier machine learning framework.

Science advances·2026
Same author

Combined influence of the QM methods, active space size, Franck-Condon approximation, Herzberg-Teller effect and Duschinsky effect on vibrationally resolved electronic spectra: insights from firefly oxyluciferin.

Physical chemistry chemical physics : PCCP·2025
Same author

Efficient evaluation of spin-orbit couplings in single-molecule magnets using DMRG within the DMET framework.

The Journal of chemical physics·2025

Related Experiment Video

Updated: Oct 7, 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

Low-Scaling Excited State Calculation Using the Block Interaction Product State.

Ke Wang1, Zhaoxuan Xie1, Zhen Luo1

  • 1School of Chemistry and Chemical Engineering, Jiangsu Key Laboratory of Vehicle Emissions Control, Nanjing University, Nanjing 210023, China.

The Journal of Physical Chemistry Letters
|January 11, 2022
PubMed
Summary

We developed a new method for calculating excited states in large molecules. This block interaction product state (BIPS) approach offers accurate, efficient, and cost-effective "black-box" computations for molecular systems.

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

8.3K
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

6.3K

Related Experiment Videos

Last Updated: Oct 7, 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

8.3K
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

6.3K

Area of Science:

  • Computational Chemistry
  • Quantum Chemistry
  • Theoretical Chemistry

Background:

  • Accurate excited state calculations are crucial for understanding molecular properties.
  • Existing methods struggle with computational cost for large molecular systems.
  • Excitonic models require efficient construction of basis sets.

Purpose of the Study:

  • To develop an automatic and efficient scheme for constructing bases for excitonic models.
  • To enable accurate "black-box" excited state structure calculations for large molecular systems.
  • To introduce the block interaction product state (BIPS) framework.

Main Methods:

  • The block interaction product state (BIPS) bases are direct products of local chromophore states.
  • Local states are determined by diagonalizing the reduced density matrix of subsystems.
  • Fragment-based calculations incorporating two- and three-body interactions were implemented.

Main Results:

  • The BIPS framework accurately describes excitation energies of low-lying excited states.
  • It also accurately predicts first-order wave function properties like dipole moments.
  • Calculations were performed on eight diverse molecular aggregates.

Conclusions:

  • The BIPS framework provides an accurate and efficient method for excited state calculations.
  • This approach significantly reduces computational cost for large molecular systems.
  • BIPS enables reliable "black-box" excited state structure predictions.