Publications de Tomislav Begusic

Applicability of the Thawed Gaussian Wavepacket Dynamics to the Calculation of Vibronic Spectra of Molecules with Double-Well Potential Energy Surfaces br

Simulating vibrationally resolved electronic spectra of anharmonic systems, especially those involving double-wellpotential energy surfaces, often requires expensive quantumdynamics methods. Here, we explore the applicability andlimitations of the recently ...

AMER CHEMICAL SOC2022

Efficient Semiclassical Dynamics for Vibronic Spectroscopy beyond Harmonic, Condon, and Zero-Temperature Approximations

Jiri Vanicek, Tomislav Begusic

Understanding light-induced processes in biological and human-made molecular systems is one of the main goals of physical chemistry. It has been known for years that the photoinduced dynamics of atomic nuclei can be studied by looking at the vibrational su ...

2021

Efficient ab initio semiclassical dynamics for linear and nonlinear electronic spectroscopy

Tomislav Begusic

Molecular spectroscopy is an essential experimental technique in both fundamental physical sciences and applied research. For example, electronic spectroscopy, in which light induces a change in the electronic state of a molecule, is a powerful tool for st ...

EPFL2021

Finite-Temperature, Anharmonicity, and Duschinsky Effects on the Two-Dimensional Electronic Spectra from Ab Initio Thermo-Field Gaussian Wavepacket Dynamics

Jiri Vanicek, Tomislav Begusic

Accurate description of finite-temperature vibrational dynamics is indispensable in the computation of two-dimensional electronic spectra. Such simulations are often based on the density matrix evolution, statistical averaging of initial vibrational states ...

2021

Ab initio semiclassical evaluation of vibrationally resolved electronic spectra with thawed Gaussians

Jiri Vanicek, Tomislav Begusic

Vibrationally resolved electronic spectra of polyatomic molecules provide valuable information about the quantum properties of both electrons and nuclei. This chapter reviews the recent progress in ab initio semiclassical calculations of such spectra, base ...

Elsevier2021

On-the-Fly ab initio Semiclassical Evaluation of Electronic Coherences in Polyatomic Molecules Reveals a Simple Mechanism of Decoherence

Jiri Vanicek, Nikolay Golubev, Tomislav Begusic

Irradiation of a molecular system by an intense laser field can trigger dynamics of both electronic and nuclear subsystems. The lighter electrons usually move on much faster, attosecond timescale but the slow nuclear rearrangement damps ultrafast electroni ...

2020

Semiclassical Approach to Photophysics Beyond Kasha’s Rule and Vibronic Spectroscopy Beyond the Condon Approximation. The Case of Azulene

Jacques-Edouard Moser, Marius Wehrle, Jiri Vanicek, Tomas Zimmermann, Julien Roulet, Antonio Prlj, Tomislav Begusic, Seonghoon Choi, Zhan Tong Zhang, George Cameron Fish

Azulene is a prototypical molecule with ananomalousfluorescence from the second excited electronic state,thus violating Kasha’s rule, and with an emission spectrum thatcannot be understood within the Condon approximation. To betterunderstand the photophysi ...

2020

On-the-fly ab initio semiclassical evaluation of vibronic spectra at finite temperature

Jiri Vanicek, Tomislav Begusic

To compute and analyze vibrationally resolved electronic spectra at zero temperature, we have recently implemented the on-the-fly ab initio extended thawed Gaussian approximation [A. Patoz et al., J. Phys. Chem. Lett. 9, 2367 (2018)], which accounts for an ...

2020

On-the-fly ab initio semiclassical evaluation of third-order response functions for two-dimensional electronic spectroscopy

Jiri Vanicek, Tomislav Begusic

Ab initio computation of two-dimensional electronic spectra is an expanding field, whose goal is improving upon simple, few-dimensional models often employed to explain experiments. Here, we propose an accurate and computationally affordable approach, base ...

2020

Single-Hessian thawed Gaussian approximation

Jiri Vanicek, Manuel Cordova, Tomislav Begusic

2019

On-the-Fly Ab Initio Semiclassical Evaluation of Absorption Spectra of Polyatomic Molecules beyond the Condon Approximation

Jiri Vanicek, Aurélien Kevin Fabrice Patoz, Tomislav Begusic

To evaluate vibronic spectra beyond the Condon approximation, we extend the on-the-fly ab initio thawed Gaussian approximation by considering the Herzberg–Teller contribution due to the dependence of the electronic transition dipole moment on nuclear coord ...

2018

On-the-fly ab initio three thawed Gaussians approximation: a semiclassical approach to Herzberg-Teller spectra

Jiri Vanicek, Aurélien Kevin Fabrice Patoz, Miroslav Sulc, Tomislav Begusic

2018

On-the-fly ab initio semiclassical evaluation of time-resolved electronic spectra

Jiri Vanicek, Julien Roulet, Tomislav Begusic

We present a methodology for computing vibrationally and time-resolved pump-probe spectra, which takes into account all vibrational degrees of freedom and is based on the combination of the thawed Gaussian approximation with on-the-fly ab initio evaluation ...

AMER INST PHYSICS2018