Publications associées à Nonadiabatic ab initio molecular dynamics using linear-response time-dependent density functional theory

High-order geometric integrators for the variational Gaussian wavepacket dynamics and application to vibronic spectra at finite temperature

Molecular quantum dynamics simulations are essential for understanding many fundamental phenomena in physics and chemistry. They often require solving the time-dependent Schrödinger equation for molecular nuclei, which is challenging even for medium-sized ...

EPFL2024

Applications of the thawed Gaussian approximation to electronic spectroscopy

Eriks Kletnieks

The exploration of electronically excited states and the study of diverse photochemical and photophysical processes are the main goals of molecular electronic spectroscopy. Exact quantum-mechanical simulation of such experiments is, however, beyond current ...

EPFL2024

Excited State-Specific CASSCF Theory for the Torsion of Ethylene

State-specific complete active space self-consistent field (SS-CASSCF) theory has emerged as a promising route to accurately predict electronically excited energy surfaces away from molecular equilibria. However, its accuracy and practicality for chemical ...

Amer Chemical Soc2024

Advancing Computational Chemistry with Stochastic and Artificial Intelligence Approaches

Justin Villard

Computational chemistry aims to simulate reactions and molecular properties at the atomic scale, advancing the design of novel compounds and materials with economic, environmental, and societal implications. However, the field relies on approximate quantum ...

EPFL2023

Modelling of metal alloys in realistic conditions with machine learning

Nataliya Lopanitsyna

Computer simulations based on statistical methods have emerged as a powerful tool for studying structure-property relationships at the atomistic level. However, to provide reliable insights into materials in realistic conditions, it is essential to accurat ...

EPFL2023

Electrokinetic, electrochemical, and electrostatic surface potentials of the pristine water liquid-vapor interface

Philip Robin Loche

Although conceptually simple, the air-water interface displays rich behavior and is subject to intense experimental and theoretical investigations. Different definitions of the electrostatic surface potential as well as different calculation methods, each ...

AIP Publishing2022

Importance of Nuclear Quantum Effects for NMR Crystallography

Michele Ceriotti, Venkat Kapil, Edgar Albert Engel

The resolving power of solid-state nuclear magnetic resonance (NMR) crystallography depends heavily on the accuracy of computational predictions of NMR chemical shieldings of candidate structures, which are usually taken to be local minima in the potential ...

AMER CHEMICAL SOC2021

Energetics and mixing of thermally driven flows in Hele-Shaw cells

Hugo Nicolás Ulloa Sánchez

Thermally driven flows in fractures play a key role in enhancing the heat transfer and fluid mixing across the Earth’s lithosphere. Yet the energy pathways in such confined environments have not been characterised. Building on Letelier et al. (J. Fluid Mec ...

Cambridge University Press2021

Machine-Learning of Atomic-Scale Properties Based on Physical Principles

Michele Ceriotti, Michael John Willatt

We briefly summarize the kernel regression approach, as used recently in materials modelling, to fitting functions, particularly potential energy surfaces, and highlight how the linear algebra framework can be used to both predict and train from linear fun ...

Springer International Publishing2020

Engineering Parallel Transmit/Receive Radio-Frequency Coil Arrays for Human Brain MRI at 7 Tesla

Jérémie Daniel Clément

Magnetic resonance imaging is widely used in medical diagnosis to obtain anatomical details of the human body in a non-invasive way. Clinical MR scanners typically operate at a static magnetic field strength (B0) of 1.5T or 3T. However, going to higher fie ...

EPFL2019

Generalized Electric Field Equations of a Time-Varying Current Distribution Based on the Electromagnetic Fields of Moving and Accelerating Charges

Marcos Rubinstein

In several studies conducted recently, it was shown that equations pertinent to the electric and magnetic fields produced by electrical charges in motion can be used to calculate the electromagnetic fields produced by current pulses propagating along linea ...

2019

Helium-induced electronic transitions in photo-excited Ba+–Hen exciplexes

Marcel Drabbels

The possibility for helium-induced electronic transitions in a photo-excited atom is investigated using Ba+ excited to the 6p 2P state as a prototypical example. A diabatization scheme has been designed to obtain the necessary potential energy surfaces and ...

2018

Kinetic isotope effects and how to describe them

Jiri Vanicek, Konstantin Karandashev

We review several methods for computing kinetic isotope effects in chemical reactions including semiclassical and quantum instanton theory. These methods describe both the quantization of vibrational modes as well as tunneling and are applied to the ⋅H + H ...

2017

Nonadiabatic effects in electronic and nuclear dynamics

Majed Chergui, Ursula Röthlisberger, Jiri Vanicek, Aurélien Kevin Fabrice Patoz, Tomas Zimmermann, Elisa Liberatore, Nicholas John Browning, Martin Peter Bircher

Due to their very nature, ultrafast phenomena are often accompanied by the occurrence of nonadiabatic effects. From a theoretical perspective, the treatment of nonadiabatic processes makes it necessary to go beyond the (quasi) static picture provided by th ...

2017

Diamond Configuration for Non-Reciprocal Transmission

Sina Khorasani

A system scheme is presented, which allows non-reciprocal wave transmission or directional amplification of electromagnetic signals, using a boxed four-node method. Edges represent strong hopping interactions and diagonals stand for weak parametric interac ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Formulation of the Field-to-Transmission Line Coupling Equations in Terms of Scalar and Vector Potentials

Farhad Rachidi-Haeri, Marcos Rubinstein

More than 60 years ago, Prof. S. Rusck introduced a coupling model to take into account the interaction of lightning-generated electromagnetic fields with overhead power transmission and distribution lines. The model which assumes that the ground is perfec ...

Institute of Electrical and Electronics Engineers2017

Nuclear Quantum Effects in H+ and OH- Diffusion along Confined Water Wires

Michele Ceriotti, Mariana Rossi Carvalho

The diffusion of protons and hydroxide ions along water wires provides an efficient mechanism for charge transport that is exploited by biological membrane channels and shows promise for technological applications such as fuel cells. However, what is lacki ...

Amer Chemical Soc2016

Nuclear Quantum Effects in Water and Aqueous Systems: Experiment, Theory, and Current Challenges

Michele Ceriotti, Wei Fang

Nuclear quantum effects influence the structure and dynamics of hydrogen-bonded systems, such as water, which impacts their observed properties with widely varying magnitudes. This review highlights the recent significant developments in the experiment, th ...

American Chemical Society2016

Locating transient disturbance sources and modelling their interaction with transmission lines : use of electromagnetic time reversal and asymptotic theory

Gaspard Lugrin

This thesis deals with the application of electromagnetic time reversal to locating transient disturbance sources and the use of the asymptotic theory for the modelling of their interaction with transmission lines. We demonstrate that the time-of-arrival, ...

EPFL2016

On-the-fly ab initio semiclassical dynamics of floppy molecules: Absorption and photoelectron spectra of ammonia

Marius Wehrle, Jiri Vanicek, Solène Oberli

We investigate the performance of on-the-fly ab initio (OTF-AI) semiclassical dynamics combined with the thawed Gaussian approximation (TGA) for computing vibrationally resolved absorption and photoelectron spectra. Ammonia is used as a prototype of floppy ...

American Chemical Society2015