title: Accurate Infrared (IR) Spectra for Molecules Containing the C≡N Moiety by Anharmonic Computations with the Double Hybrid B2PLYP Density Functional.
abstract: Herein, we report a comprehensive benchmark of C≡N stretching vibrations computed at harmonic and anharmonic levels with the aim of proposing and validating a reliable computational strategy to get accurate results for this puzzling vibrational mode without any ad hoc scaling factor. Anharmonic calculations employing second-order vibrational perturbation theory provide very good results when performed using the B2PLYP double-hybrid functional, in conjunction with an extended basis set and supplemented by semiempirical dispersion contributions. For larger systems, B2PLYP harmonic frequencies, together with B3LYP anharmonic corrections, offer a very good compromise between accuracy and computational cost without the need of any empirical scaling factor.
authors.affiliation: Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
authors.forename: Fanny
authors.initials: F
authors.lastname: Vazart
authors.affiliation: Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
authors.forename: Camille
authors.initials: C
authors.lastname: Latouche
authors.affiliation: Dipartimento di Farmacia (DIFARMA), Università di Salerno , via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Cimino
authors.affiliation: Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barone
mesh_terms: D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D014732:Vibration
chemical_list: D009570:Nitriles