0000000000122527

AUTHOR

Benjamin Lasorne

showing 4 related works from this author

A quantum dynamics study of the benzopyran ring opening guided by laser pulses

2014

Abstract The ring-opening photoisomerization of benzopyran, which occurs via a photochemical route involving a conical intersection, has been studied with quantum dynamics calculations using the multi-configuration time-dependent Hartree method (MCTDH). We introduce a mechanistic strategy to control the conversion of benzopyran to merocyanine with laser pulses. We use a six-dimensional model developed in a previous work for the potential energy surfaces (PES) based on an extension of the vibronic-coupling Hamiltonian model (diabatization method by ansatz), which depends on the most active degrees of freedom. The main objective of these quantum dynamics simulations is to provide a set of str…

010304 chemical physicsChemistryQuantum dynamicsDegrees of freedom (physics and chemistry)General Physics and AstronomyHartreeConical intersection010402 general chemistry01 natural sciencesPotential energyMolecular physics0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistrysymbols.namesakeStark effectComputational chemistry0103 physical sciences[ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistrysymbolsPhysical and Theoretical ChemistryGround stateAdiabatic processComputingMilieux_MISCELLANEOUS
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Laser control of the radiationless decay in pyrazine using the dynamic Stark effect

2014

The laser control of the radiationless decay between the B(3u)(nπ*) and B(2u)(ππ*) states of pyrazine using the dynamic Stark effect has been investigated. A vibronic coupling model Hamiltonian in diabatic representation, including potential energy, transition dipole, and static polarizability surfaces as a function of the four most important vibrational modes of the molecule has been parametrized using multi-reference electronic structure calculations. The interaction of the molecule with a strong non-resonant laser pulse has been analyzed in terms of dressed potential energy surfaces. Because of the large polarizability difference between the vibronically coupled B(3u)(nπ*) and B(2u)(ππ*)…

PyrazineChemistryTransition dipole momentGeneral Physics and AstronomyLaserlaw.invention[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistrysymbols.namesakechemistry.chemical_compoundStark effectlawExcited stateLaser coolingQuantum mechanics[ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistrysymbolsPhysical and Theoretical ChemistryAtomic physicsComputingMilieux_MISCELLANEOUS
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The role of the low-lying dark np* states in the photophysics of pyrazine: a quantum dynamics study

2014

The excited state dynamics of pyrazine has attracted considerable attention in the last three decades. It has long been recognized that after UV excitation, the dynamics of the molecule is impacted by strong non-adiabatic effects due to the existence of a conical intersection between the B2u(ππ*) and B3u(nπ*) electronic states. However, a recent study based on trajectory surface hopping dynamics simulations suggested the participation of the Au(nπ*) and B2g(nπ*) low-lying dark electronic states in the ultrafast radiationless decay of the molecule after excitation to the B2u(ππ*) state. The purpose of this work was to pursue the investigation of the role of the Au(nπ*) and B2g(nπ*) states in…

education.field_of_study010304 chemical physicsPyrazineChemistryQuantum dynamicsPopulationGeneral Physics and AstronomySurface hoppingElectronic structureConical intersection010402 general chemistry7. Clean energy01 natural sciences0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryVibronic couplingchemistry.chemical_compoundExcited state0103 physical sciences[ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistryPhysical and Theoretical ChemistryAtomic physicseducationComputingMilieux_MISCELLANEOUS
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Full-dimensional control of the radiationless decay in pyrazine using the dynamic Stark effect

2014

We present a full quantum-mechanical study of the laser control of the radiationless decay between the B3u(nπ(*)) and B2u(ππ(*)) states of pyrazine using the dynamic Stark effect. In contrast to our previous study [Sala et al., J. Chem. Phys. 140, 194309 (2014)], where a four-dimensional model was used, all the 24 degrees of freedom are now included in order to test the robustness of the strategy of control. Using a vibronic coupling Hamiltonian model in a diabatic representation, the multi-layer version of the multi-configuration time-dependent Hartree method is exploited to propagate the corresponding wave packets. We still observe a trapping of the wavepacket on the B2u(ππ(*)) potential …

010304 chemical physicsChemistryWave packetDiabaticGeneral Physics and AstronomyHartree010402 general chemistry01 natural sciencesPotential energy0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryVibronic couplingsymbols.namesakeStark effectQuantum mechanicsExcited state[ CHIM.THEO ] Chemical Sciences/Theoretical and/or physical chemistry0103 physical sciencesPotential energy surfacesymbolsPhysics::Atomic PhysicsPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsComputingMilieux_MISCELLANEOUSThe Journal of Chemical Physics
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