Computational formulas for symmetry-forbidden vibronic spectra and their application n-π* transition in neat acetone
Journal
Journal of Chemical Physics
Journal Volume
115
Journal Issue
9
Pages
4080-4094
Date Issued
2001
Author(s)
Abstract
In this study theoretical expressions are derived to investigate the non-Condon effect for symmetry-forbidden optical transition using displaced�Vdistorted harmonic potential energy surfaces. These expressions can efficiently cope with multipromoting modes and multielectronic states involved in the non-Condon effect at a finite temperature. Ab initio and molecular dynamics calculation results can be directly invoked into the formulas. Based on the proposed formulas, the temperature dependence of the interference effects of multipromoting modes on the non-Condon optical linear spectra is investigated. To demonstrate the computational formulas, the optical absorption and dispersion fluorescence spectra for the forbidden transition of neat acetone, A11�VA21(n�V�k*), are also studied. Simulation results indicate that the vibrational frequency of CH3 torsion mode of acetone plays an important role in the optical spectra. Moreover, the electronic energy gap (adiabatic transition), the Stokes shift caused by environmental interaction, and the average Huang�VRhys factor for intermolecular modes in neat acetone are obtained as 29 900 cm?1, 5400 cm?1, and 0.607, respectively.
SDGs
Type
journal article