Related Experiment Video
Updated: Nov 23, 2025
10:35
Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
9.0K
Excited state diabatization on the cheap using DFT: Photoinduced electron and hole transfer
Yuezhi Mao1, Andrés Montoya-Castillo1, Thomas E Markland1
1Department of Chemistry, Stanford University, Stanford, California 94305, USA.
The Journal of Chemical Physics
|December 31, 2020
Summary
We developed a new density functional theory (DFT) method to accurately calculate excited state electron and hole transfer. This approach efficiently models complex photochemical processes in various systems.
Area of Science:
- Physical Chemistry
- Quantum Chemistry
- Computational Chemistry
Background:
- Excited state electron and hole transfer are crucial for processes like solar energy conversion and photosynthesis.
- Simulating these processes requires accurate diabatic states, which are challenging to obtain with current methods.
- Existing computational approaches often suffer from inaccuracies or high costs.
Purpose of the Study:
- To introduce a novel, accurate, and efficient DFT-based diabatization scheme for excited states.
- To enable reliable simulation and understanding of photoinduced electron and hole transfer.
- To overcome limitations of existing methods in calculating diabatic states and couplings.
Main Methods:
- Developed a new DFT-based diabatization scheme, Δ-ALMO(MSDFT2).
- Utilizes Absolutely Localized Molecular Orbitals (ALMOs) to construct diabatic states.
- Combines ALMO calculations with the ΔSCF technique and MSDFT2 for couplings.
Main Results:
- The Δ-ALMO(MSDFT2) method accurately calculates excited state electron and hole transfer for various systems.
- Demonstrated accuracy for DNA repair, charge separation, chromophore-solvent transfer, and singlet fission.
- The method is efficient for both charged and uncharged systems.
Conclusions:
- The Δ-ALMO(MSDFT2) framework provides an accurate and efficient route to excited state diabatization.
- Enables simulation and elucidation of photoinduced electron and hole transfer in complex systems.
- Offers a valuable tool for studying condensed-phase photochemical processes.
Related Concept Videos
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.0K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.0K
01:25Deactivation Processes: Jablonski Diagram
1.3K
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...
1.3K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.7K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.7K
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
11.5K
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
11.5K
02:13Energy Diagrams, Transition States, and Intermediates
18.8K
Free-energy diagrams, or reaction coordinate diagrams, are graphs showing the energy changes that occur during a chemical reaction. The reaction coordinate represented on the horizontal axis shows how far the reaction has progressed structurally. Positions along the x-axis close to the reactants have structures resembling the reactants, while positions close to the products resemble the products. Peaks on the energy diagram represent stable structures with measurable lifetimes, while...
18.8K
01:14Molecular Spectroscopy: Absorption and Emission
4.0K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
4.0K