Abstract
We present a method to calculate both on- and off-resonance vibrational Raman optical activities (VROAs) of molecules using time-dependent density functional theory. This is an extension of a method to calculate the normal VROA by including a finite lifetime of the electronic excited states in all calculated properties. The method is based on a short-time approximation to Raman scattering and is, in the off-resonance case, identical to the standard theory of Placzek. The normal and resonance VROA spectra are calculated from geometric derivatives of the different generalized polarizabilites obtained using linear response theory which includes a damping term to account for the finite lifetime. Gauge-origin independent results for normal VROA have been ensured using either the modified-velocity gauge or gauge-included atomic orbitals. For the resonance VROA only the modified-velocity gauge has been implemented. We present some initial results for H2 O2 and (S)-methyloxirane and compare with predictions from a simple two-state approximation.
Original language | English (US) |
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Article number | 134101 |
Journal | Journal of Chemical Physics |
Volume | 127 |
Issue number | 13 |
DOIs | |
State | Published - 2007 |
Funding
Two of the authors (L.J. and G.C.S.) thank the Air Force Office of Scientific Research MURI program (No. F49620-02-1-0381) and the DTRA JSTO Program (No. FA9550-06-1-0558). One of the authors (J.A.) acknowledges the CAREER program of the National Science Foundation (Grant No. CHE-0447321) for financial support of this research.
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry