eprintid: 10198987
rev_number: 9
eprint_status: archive
userid: 699
dir: disk0/10/19/89/87
datestamp: 2024-10-28 11:59:50
lastmod: 2024-10-28 11:59:50
status_changed: 2024-10-28 11:59:50
type: article
metadata_visibility: show
sword_depositor: 699
creators_name: Cigrang, Leon LE
creators_name: Worth, Graham A
title: Modeling Photodissociation: Quantum Dynamics Simulations of Methanol
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F56
keywords: Science & Technology, Physical Sciences, Chemistry, Physical, Physics, Atomic, Molecular & Chemical, Chemistry, Physics, NONADIABATIC DIRECT-DYNAMICS, PHOTOCHEMISTRY, SPECTROSCOPY, PATHWAYS, ENERGY
note: Copyright © 2024 The Authors. Published by American Chemical Society. This publication is licensed under 
CC-BY 4.0 .
abstract: A comprehensive computational study of the gas-phase photodissociation dynamics of methanol is presented. Using a multiconfigurational active space based method (RASSCF) to obtain multidimensional potential energy surfaces (PESs) on-the-fly, direct quantum dynamics simulations were run using the variational multi-configurational Gaussian method (DD-vMCG). Different initial excitation energies were simulated to investigate the dependence of the branching ratios on the electronic state being populated. A detailed mechanistic explanation is provided for the observed differences with respect to the excitation energy. Population of the lowest lying excited state of methanol leads to rapid hydroxyl hydrogen loss as the main dissociation channel. This is rationalized by the strongly dissociative nature of the PES cut along the O-H stretching coordinate, confirmed by the broad feature in the absorption spectrum. In contrast, more energetic excitations lead mainly to C-O bond breaking. Again, analysis of the diabatic surfaces offers a clear explanation in terms of the nature of the electronic states involved and the coupling between them. The type of calculations presented, as well as the subsequent analysis of the results, should be seen as a general workflow for the modeling of photochemical reactions.
date: 2024-08-28
date_type: published
publisher: AMER CHEMICAL SOC
official_url: http://dx.doi.org/10.1021/acs.jpca.4c03612
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2308609
doi: 10.1021/acs.jpca.4c03612
medium: Print-Electronic
lyricists_name: Worth, Graham
lyricists_id: GWORT12
actors_name: Worth, Graham
actors_id: GWORT12
actors_role: owner
funding_acknowledgements: EP/X026973/1 [EPSRC programme]
full_text_status: public
publication: The Journal of Physical Chemistry A
volume: 128
number: 36
pagerange: 7546-7557
pages: 12
event_location: United States
issn: 1089-5639
citation:        Cigrang, Leon LE;    Worth, Graham A;      (2024)    Modeling Photodissociation: Quantum Dynamics Simulations of Methanol.                   The Journal of Physical Chemistry A , 128  (36)   pp. 7546-7557.    10.1021/acs.jpca.4c03612 <https://doi.org/10.1021/acs.jpca.4c03612>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10198987/1/Worth_2024-modeling-photodissociation-quantum-dynamics-simulations-of-methanol%20%281%29.pdf