Predicting the photodynamics of cyclobutanone triggered by a laser pulse at 200 nm and its MeV-UED signals—A trajectory surface hopping and XMS-CASPT2 perspective

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F24%3A43929146" target="_blank" >RIV/60461373:22340/24:43929146 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1063/5.0203105" target="_blank" >https://doi.org/10.1063/5.0203105</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0203105" target="_blank" >10.1063/5.0203105</a>

Result language

angličtina

Original language name

Predicting the photodynamics of cyclobutanone triggered by a laser pulse at 200 nm and its MeV-UED signals—A trajectory surface hopping and XMS-CASPT2 perspective

Original language description

This work is part of a prediction challenge that invited theoretical/computational chemists to predict the photochemistry of cyclobutanone in the gas phase, excited at 200 nm by a laser pulse, and the expected signal that will be recorded during a time-resolved megaelectronvolt ultrafast electron diffraction (MeV-UED). We present here our theoretical predictions based on a combination of trajectory surface hopping with XMS-CASPT2 (for the nonadiabatic molecular dynamics) and Born-Oppenheimer molecular dynamics with MP2 (for the athermal ground-state dynamics following internal conversion), coined (NA+BO)MD. The initial conditions were sampled from Born-Oppenheimer molecular dynamics coupled to a quantum thermostat. Our simulations indicate that the main photoproducts after 2 ps of dynamics are CO + cyclopropane (50%), CO + propene (10%), and ethene and ketene (34%). The photoexcited cyclobutanone in its second excited electronic state S 2 can follow two pathways for its nonradiative decay: (i) a ring-opening in S 2 and a subsequent rapid decay to the ground electronic state, where the photoproducts are formed, or (ii) a transfer through a closed-ring conical intersection to S 1 , where cyclobutanone ring opens and then funnels to the ground state. Lifetimes for the photoproduct and electronic populations were determined. We calculated a stationary MeV-UED signal [difference pair distribution function— Δ PDF ( r ) ] for each (interpolated) pathway as well as a time-resolved signal [ Δ PDF ( r , t ) and Δ I / I ( s , t ) ] for the full swarm of (NA+BO)MD trajectories. Furthermore, our analysis provides time-independent basis functions that can be used to fit the time-dependent experimental UED signals [both Δ PDF ( r , t ) and Δ I / I ( s , t ) ] and potentially recover the population of photoproducts. We also offer a detailed analysis of the limitations of our model and their potential impact on the predicted experimental signals. © 2024 Author(s).

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

<a href="/en/project/GA23-07066S" target="_blank" >GA23-07066S: Time-dependent simulations for time-resolved electronic spectroscopies</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

JOURNAL OF CHEMICAL PHYSICS

ISSN

0021-9606

e-ISSN

—

Volume of the periodical

160

Issue of the periodical within the volume

14

Country of publishing house

US - UNITED STATES

Number of pages

17

Pages from-to

144305

UT code for WoS article

001198859200013

EID of the result in the Scopus database

2-s2.0-85190118942