Solvent Effects on Nonadiabatic Dynamics: Ab Initio Multiple Spawning Propagated on CASPT2/xTB Potentials

Journal of Chemical Theory and Computation, Год журнала: 2025, Номер unknown

Опубликована: Фев. 11, 2025

An approach to simulate nonadiabatic dynamics in solution is introduced, which relies on the propagation of nuclear wavepacket with Ab Initio Multiple Spawning (AIMS) method under effect potential energy calculated a hybrid but fully quantum mechanical scheme (QM/QM′). The electronic energies excited states chromophore are multireference perturbation theory (CASPT2), and embedding molecules described tight binding Hamiltonian (GFN2-xTB). This implementation open source combination PySpawn, OpenMolcas, xTB. Additionally, ORCA used properly generate initial conditions solution, showing how cutting-edge implementations several commonly software can push state art toward new high standard accuracy. ethylene vacuum, acetone, chloroform reported as test case, detailed analysis AIMS runs that shows important geometrical effects solvents decay mechanism chromophore.

Язык: Английский

On-the-fly simulations of transient absorption pump–probe spectra: Combining mapping dynamics with doorway-window protocol

The Journal of Chemical Physics, Год журнала: 2025, Номер 162(20)

Опубликована: Май 27, 2025

We have constructed an ab initio protocol for the simulation of transient-absorption (TA) pump–probe (PP) signals realistic polyatomic systems. The is based on interfacing doorway-window representation spectroscopic with on-the-fly mapping Hamiltonian dynamics approach at symmetrical quasi-classical/Meyer–Miller level. methodology applied to TA PP two molecular systems, azobenzene and cis-hepta-3,5,7-trieniminium cation. For both molecules, spectra were demonstrated give a direct fingerprint excited state wavepacket internal conversion, which permits monitoring isomerization pathways en route final photoproducts.

Язык: Английский

Simulation of the non-adiabatic dynamics of an enone-Lewis acid complex in an explicit solvent

Physical Chemistry Chemical Physics, Год журнала: 2024, Номер 26(35), С. 23256 - 23263

Опубликована: Янв. 1, 2024

Lewis acid catalysis is a promising tool in photochemistry. Thus, the ultrafast dynamics of substrate-Lewis complex investigated silico , which reveals an intriguing dissociation–reassociation mechanism.

Язык: Английский