title: Effects of the basis set and of the exchange-correlation functional on the Inelastic Electron Tunneling signatures of 1,4-benzenedithiol.
abstract: The effects of the atomic basis set and of the exchange-correlation (XC) functional on the Inelastic Electron Tunneling (IET) spectra have been investigated by considering the prototypical 1,4-benzenedithiol molecule. These studies have been completed by tackling the reliability of the same methods for predicting the IR absorption spectrum of the same molecule. The main conclusions are (i) the B3LYP XC functional is suitable to predict the relative vibrational frequencies, (ii) provided a scaling factor is used, the root mean square error on the vibrational frequencies goes down to 18 cm(-1), (iii) triple-ζ basis sets and in particular the cc-pVTZ basis set is a good compromise between accuracy and computational needs, (iv) basis set effects on the IET intensities are larger than those of the XC functional, and (v) the cc-pVTZ, cc-pVQZ, and aug-cc-pVDZ basis sets provide consistent IET intensities.
authors.affiliation: Laboratoire de Chimie Théorique, Unité de Chimie Physique Théorique et Structurale, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Audrey
authors.initials: A
authors.lastname: Ségerie
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Lin
authors.forename: Vincent
authors.initials: V
authors.lastname: Liégeois
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.forename: Benoît
authors.initials: B
authors.lastname: Champagne
mesh_terms: D000465:Algorithms; D004583:Electrons; D013055:Spectrophotometry, Infrared / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: C516314:1,4-benzenedithiol; D013438:Sulfhydryl Compounds
keywords: First principles calculations; Inelastic Electron Tunneling; Infrared spectra; Vibrational spectra