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.
|Titolo:||Anharmonic calculations of vibrational spectra for molecular adsorbates: A divide-and-conquer semiclassical molecular dynamics approach|
CAZZANIGA, MARCO (Primo)
MICCIARELLI, MARCO (Secondo)
GABAS, FABIO (Penultimo)
CEOTTO, MICHELE (Ultimo) (Corresponding)
|Parole Chiave:||initial-value representation; titanium-dioxide photocatalysis; anatase TIO2; surface science; quantum propagation; water-adsorption; metal-oxides; nitric-oxide; hydrogen; CO|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Progetto:||Divide and Conquer ad initio semiclassical molecular dynamics for spectropic calculations of complex systems (SEMICOMPLEX)|
Studio teorico-computazionale della bonifica fotocatalitica di atmosfere inquinate (QURE)
|Data di pubblicazione:||14-mar-2020|
|Data ahead of print / Data di stampa:||25-feb-2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1063/1.5142682|
|Appare nelle tipologie:||01 - Articolo su periodico|