title: Simulation of Vacuum UV Absorption and Electronic Circular Dichroism Spectra of Methyl Oxirane: The Role of Vibrational Effects.
abstract: Vibrationally resolved one-photon absorption and electronic circular dichroism spectra of (R)-methyl oxirane were calculated with different electronic and vibronic models selecting, through an analysis of the convergence of the results, the best compromise between reliability and computational cost. Linear-response TD-DFT/CAM-B3LYP/SNST electronic computations in conjunction with the simple vertical gradient vibronic model were chosen and employed for systematic comparison with the available experimental data. Remarkable agreement between simulated and experimental spectra was achieved for both one-photon absorption and circular dichroism concerning peak positions, relative intensities, and general spectral shapes considering the computational efficiency of the chosen theoretical approach. The significant improvement of the results with respect to smearing of vertical electronic transitions by phenomenological Gaussian functions and the possible inclusion of solvent effects by polarizable continuum models at a negligible additional cost paves the route toward the simulation and analysis of spectral shapes of complex molecular systems in their natural environment.
authors.affiliation: Scuola Normale Superiore , Piazza dei Cavalieri 7, 56126 Pisa, Italy.|Interdisciplinary Center for Scientific Computing, Heidelberg University , Im Neuenheimer Feld 368, 69120 Heidelberg, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Hodecker
authors.affiliation: International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University , 99 Shangda Road, 200444 Shanghai, China.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Biczysko
authors.affiliation: Interdisciplinary Center for Scientific Computing, Heidelberg University , Im Neuenheimer Feld 368, 69120 Heidelberg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Dreuw
authors.affiliation: Scuola Normale Superiore , Piazza dei Cavalieri 7, 56126 Pisa, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Barone