Excited States of Xanthophylls Revisited: Toward the Simulation of Biologically Relevant Systems
Mattia Bondanza, Denis Jacquemin, Benedetta Mennucci
Abstract
methods (CC3 and DMRG/NEVPT2) with time-dependent DFT and semiempirical CI (SECI) on model keto-carotenoids and show that SECI represents the right compromise between accuracy and computational cost to be applied to real xanthophylls in their biological environment. As an example, we investigate canthaxanthin in the orange carotenoid protein and show that the conical intersections between excited states and excited-ground states are mostly determined by the effective bond length alternation coordinate, which is significantly tuned by the protein through geometrical constraints and electrostatic effects.
Topics & Concepts
XanthophyllExcited stateAb initioChemistryDiabaticPhotochemistryCanthaxanthinDensity functional theoryComputational chemistryChemical physicsBiological systemCarotenoidAtomic physicsPhysicsQuantum mechanicsBiologyOrganic chemistryBiochemistryAstaxanthinAdiabatic processPhotosynthetic Processes and MechanismsAntioxidant Activity and Oxidative StressSpectroscopy and Quantum Chemical Studies