DFT studies of ethylene in femtosecond laser pulses

TL;DR

This study employs time-dependent density functional theory to simulate and analyze the ultrafast laser-induced dynamics and ionization processes in ethylene molecules, highlighting the importance of coupled electronic and ionic motions.

Contribution

It introduces a reliable computational approach combining TDDFT with molecular dynamics to investigate ethylene's response to femtosecond laser pulses, emphasizing the role of ionic motion.

Findings

Ionization is significantly affected by ionic motion.

Coulomb fragmentation depends on laser frequency.

Laser pulse length influences excitation dynamics.

Abstract

Using time-dependent density functional theory, applied to valence electrons, coupled non-adiabatically to molecular dynamics of the ions, we study the induced dynamics of ethylene subjected to the laser field. We demonstrate the reliable quality of such an approach in comparison to the experimental data on atomic and molecular properties. The impact of ionic motion on the ionization is discussed showing the importance of dealing with electronic and ionic degrees of freedom simultaneously. We explore the various excitation scenarios of ethylene as a function of the laser parameters. We find that the Coulomb fragmentation depends sensitively on the laser frequency. The high laser intensity can cause brute-force Coulomb explosion and the laser pulse length actually has influence on the excitation dynamics of ethylene.