Related Experiment Videos
Density functional response theory calculations of three-photon absorption.
Peter Cronstrand1, Branislav Jansik, Dan Jonsson
1Theoretical Chemistry, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm, Sweden.
The Journal of Chemical Physics
|November 13, 2004
Summary
Density functional theory (DFT) accurately predicts three-photon absorption (3PA) probabilities for many systems. This method shows good agreement with highly correlated models, making it suitable for predicting 3PA in complex molecules.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Materials Science
Background:
- Three-photon absorption (3PA) is a nonlinear optical process with applications in advanced imaging and materials.
- Accurate theoretical prediction of 3PA probabilities is crucial for designing new materials.
Purpose of the Study:
- To assess the accuracy of density functional theory (DFT) for calculating three-photon absorption (3PA) probabilities.
- To benchmark DFT against Hartree-Fock (HF) and coupled cluster (CC) methods.
- To investigate 3PA in substituted pi-conjugated systems.
Main Methods:
- Calculation of 3PA probabilities using DFT with cubic response functions.
- Comparison of DFT results with HF and CC methods.
- Application to trans-stilbene and dithienothiophene based systems.
Main Results:
- DFT provides sufficient agreement with highly correlated methods for 3PA predictions, except near resonance.
- Noticeable differences in 3PA magnitudes were observed between HF and DFT for larger systems.
- Dipolar structures (TS-AD, DTT-AD) exhibit significantly larger 3PA values.
Conclusions:
- DFT is a viable and accurate method for predicting 3PA beyond simple few-state models.
- The findings support the use of DFT for rational design of materials with enhanced nonlinear optical properties.
- Molecular design principles for 3PA are similar to those for 2PA, favoring dipolar structures.