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Polarizable Embedded RI-CC2 Method for Two-Photon Absorption Calculations
Dalibor Hršak1, Alireza Marefat Khah2, Ove Christiansen1
1Center for Oxygen Microscopy and Imaging, Aarhus University , Langelandsgade 140, 8000 Aarhus, Denmark.
Journal of Chemical Theory and Computation
|November 18, 2015
Summary
A new polarizable embedded resolution-of-identity coupled cluster singles and approximate doubles (PERI-CC2) method accurately calculates two-photon absorption (TPA) spectra for large molecules. This efficient method is suitable for complex systems like proteins.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Spectroscopy
Background:
- Accurate calculation of two-photon absorption (TPA) spectra is crucial for understanding molecular properties and interactions.
- Existing methods may struggle with computational cost for large molecular systems.
Purpose of the Study:
- To introduce and validate a novel computational method, PERI-CC2, for calculating TPA spectra.
- To assess the efficiency and accuracy of PERI-CC2 for diverse molecular systems, including solvated molecules and proteins.
Main Methods:
- Development of a polarizable embedded resolution-of-identity coupled cluster singles and approximate doubles (PERI-CC2) method.
- Benchmarking PERI-CC2 against established methods (PE-CC2, PE-CCSD) using formamide and uracil in aqueous solution.
- Application of PERI-CC2 to calculate TPA spectra of channelrhodopsin (ChR) protein mutants.
Main Results:
- PERI-CC2 shows excellent agreement with PE-CC2 and good agreement with PE-CCSD for formamide.
- The method accurately describes the influence of hydrogen bonding on TPA spectra, as demonstrated with uracil.
- PERI-CC2 proves to be well-suited and efficient for computational studies of proteins with medium-sized chromophores.
Conclusions:
- The PERI-CC2 method offers a computationally efficient and accurate approach for determining TPA spectra of large molecular systems.
- PERI-CC2 is a valuable tool for studying electronic transitions and environmental effects in complex biological molecules.
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