title: Simulation of the resonance Raman spectrum for uracil.
abstract: The resonance Raman spectrum of uracil is simulated using the Herzberg-Teller short-time dynamics formalism. The ground-state geometry is optimized at the levels of PBE0/aug-cc-pVTZ and B3LYP/aug-cc-pVTZ, respectively. The gradient of the bright excited state is computed using time-dependent density functional theory and spin-flip time-dependent density functional theory. The excited-state calculations are carried out in both the gas phase and implicit water using the conductor-like polarizable continuum model. The ground-state equilibrium structure is found to impact the resulting resonance Raman spectrum significantly. The simulated resonance Raman spectrum using the long-range corrected functionals, that is, CAMB3LYP and LC-BLYP, and based on the PBE0/aug-cc-pVTZ optimized ground-state structure shows better agreement with the experimental spectrum than using standard hybrid functionals, that is, PBE0 and B3LYP. The solvation effect leads to a change in the energetic order of the n → π* and π → π* excited states, and it improves the agreement with the experimental spectrum, especially with regard to the relative intensities of the peaks with frequencies greater than 1600 cm(-1).
authors.affiliation: Department of Chemistry, University of Alberta , 11227 Saskatchewan Drive NW, Edmonton, AB T6G 2G2, Canada.
authors.forename: Shuai
authors.initials: S
authors.lastname: Sun
authors.forename: Alex
authors.initials: A
authors.lastname: Brown
mesh_terms: D003198:Computer Simulation; D005740:Gases / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D013059:Spectrum Analysis, Raman; D014498:Uracil / Q000737:chemistry*; D014732:Vibration; D014867:Water / Q000737:chemistry
chemical_list: D005740:Gases; D014867:Water; D014498:Uracil