The vibrational spectroscopy of adsorbates is becoming an important investigation tool for catalysis and material science. This paper presents a semiclassical molecular dynamics method able to reproduce the vibrational energy levels of systems composed by molecules adsorbed on solid surfaces. Specifically, we extend our divide-and-conquer semiclassical method for power spectra calculations to gas-surface systems and interface it with plane-wave electronic structure codes. The Born-Oppenheimer classical dynamics underlying the semiclassical calculation is full dimensional, and our method includes not only the motion of the adsorbate but also those of the surface and the bulk. The vibrational spectroscopic peaks related to the adsorbate are accounted together with the most coupled phonon modes to obtain spectra amenable to physical interpretations. We apply the method to the adsorption of CO, NO, and H2O on the anatase-TiO2 (101) surface. We compare our semiclassical results with the single-point harmonic estimates and the classical power spectra obtained from the same trajectory employed in the semiclassical calculation. We find that CO and NO anharmonic effects of fundamental vibrations are similarly reproduced by the classical and semiclassical dynamics and that H2O adsorption is fully and properly described in its overtone and combination band relevant components only by the semiclassical approach.

Anharmonic calculations of vibrational spectra for molecular adsorbates: A divide-and-conquer semiclassical molecular dynamics approach / M. Cazzaniga, M. Micciarelli, F. Moriggi, A. Mahmoud, F. Gabas, M. Ceotto. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 152:10(2020 Mar 14), pp. 104104.1-104104.14. [10.1063/1.5142682]

Anharmonic calculations of vibrational spectra for molecular adsorbates: A divide-and-conquer semiclassical molecular dynamics approach

M. Cazzaniga
Primo
;
M. Micciarelli
Secondo
;
F. Moriggi;A. Mahmoud;F. Gabas
Penultimo
;
M. Ceotto
Ultimo
2020

Abstract

The vibrational spectroscopy of adsorbates is becoming an important investigation tool for catalysis and material science. This paper presents a semiclassical molecular dynamics method able to reproduce the vibrational energy levels of systems composed by molecules adsorbed on solid surfaces. Specifically, we extend our divide-and-conquer semiclassical method for power spectra calculations to gas-surface systems and interface it with plane-wave electronic structure codes. The Born-Oppenheimer classical dynamics underlying the semiclassical calculation is full dimensional, and our method includes not only the motion of the adsorbate but also those of the surface and the bulk. The vibrational spectroscopic peaks related to the adsorbate are accounted together with the most coupled phonon modes to obtain spectra amenable to physical interpretations. We apply the method to the adsorption of CO, NO, and H2O on the anatase-TiO2 (101) surface. We compare our semiclassical results with the single-point harmonic estimates and the classical power spectra obtained from the same trajectory employed in the semiclassical calculation. We find that CO and NO anharmonic effects of fundamental vibrations are similarly reproduced by the classical and semiclassical dynamics and that H2O adsorption is fully and properly described in its overtone and combination band relevant components only by the semiclassical approach.
initial-value representation; titanium-dioxide photocatalysis; anatase TIO2; surface science; quantum propagation; water-adsorption; metal-oxides; nitric-oxide; hydrogen; CO
Settore CHIM/02 - Chimica Fisica
   Divide and Conquer ad initio semiclassical molecular dynamics for spectropic calculations of complex systems (SEMICOMPLEX)
   SEMICOMPLEX
   EUROPEAN COMMISSION
   H2020
   647107

   Studio teorico-computazionale della bonifica fotocatalitica di atmosfere inquinate (QURE)
   QURE
   MINISTERO DELL'ISTRUZIONE E DEL MERITO
   R16KN7XBRB
14-mar-2020
25-feb-2020
Article (author)
File in questo prodotto:
File Dimensione Formato  
JCP19-AR-05176R_Merged_PDF.pdf

accesso aperto

Tipologia: Pre-print (manoscritto inviato all'editore)
Dimensione 2.17 MB
Formato Adobe PDF
2.17 MB Adobe PDF Visualizza/Apri
1.5142682.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 3.61 MB
Formato Adobe PDF
3.61 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/724592
Citazioni
  • ???jsp.display-item.citation.pmc??? 6
  • Scopus 20
  • ???jsp.display-item.citation.isi??? 18
social impact