Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Fully anharmonic infrared cascade spectra of polycyclic aromatic hydrocarbons
Lawrence Berkeley Natl Lab, Chem Sci Div, Berkeley, CA 94720 USA.;Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands..
KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology. Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands.
Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands..
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA..
Show others and affiliations
2018 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 149, no 13, article id 134302Article in journal (Refereed) Published
Abstract [en]

The infrared (IR) emission of polycyclic aromatic hydrocarbons (PAHs) permeates our universe; astronomers have detected the IR signatures of PAHs around many interstellar objects. The IR emission of interstellar PAHs differs from their emission as seen under conditions on Earth as they emit through a collisionless cascade down through their excited vibrational states from high internal energies. The difficulty in reproducing interstellar conditions in the laboratory results in a reliance on theoretical techniques. However, the size and complexity of PAHs require careful consideration when producing the theoretical spectra. In this work, we outline the theoretical methods necessary to lead to fully theoretical IR cascade spectra of PAHs including: an anharmonic second order vibrational perturbation theory treatment, the inclusion of Fermi resonances through polyads, and the calculation of anharmonic temperature band shifts and broadenings (including resonances) through a Wang-Landau approach. We also suggest a simplified scheme to calculate vibrational emission spectra that retain the essential characteristics of the full IR cascade treatment and can directly transform low temperature absorption spectra in IR cascade spectra. Additionally we show that past astronomical models were in error in assuming a 15 cm(-1) correction was needed to account for anharmonic emission effects.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2018. Vol. 149, no 13, article id 134302
National Category
Physical Sciences Chemical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-237097DOI: 10.1063/1.5038725ISI: 000446815600020PubMedID: 30292208Scopus ID: 2-s2.0-85054303797OAI: oai:DiVA.org:kth-237097DiVA, id: diva2:1258428
Note

QC 20181022

Available from: 2018-10-24 Created: 2018-10-24 Last updated: 2018-10-24Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMedScopus

Search in DiVA

By author/editor
Chen, Tao
By organisation
Theoretical Chemistry and Biology
In the same journal
Journal of Chemical Physics
Physical SciencesChemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 9 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf