Mixed semiclassical initial value representation time-averaging propagator for spectroscopic calculations
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
A mixed semiclassical initial value representation expression for spectroscopic calculations is derived. The formulation takes advantage of the time-averaging filtering and the hierarchical properties of different trajectory based propagation methods. A separable approximation is then introduced that greatly reduces (about an order of magnitude) the computational cost compared with a full Herman-Kluk time-averaging semiclassical calculation for the same systems. The expression is exact for the harmonic case and it is tested numerically for a Morse potential coupled to one or two additional harmonic degrees of freedom. Results are compared to full Herman-Kluk time-averaging calculations and exact quantum wavepacket propagations. We found the peak positions of the mixed semiclassical approximations to be always in very good agreement with full quantum calculations, while overtone peak intensities are lower with respect to the exact ones. Given the reduced computational effort required by this new mixed semiclassical approximation, we believe the present method to make spectroscopic calculations available for higher dimensional systems than accessible before. (C) 2016 AIP Publishing LLC.
Details
Original language | English |
---|---|
Article number | 094102 |
Number of pages | 12 |
Journal | Journal of Chemical Physics |
Volume | 144 |
Issue number | 9 |
Publication status | Published - 7 Mar 2016 |
Peer-reviewed | Yes |
External IDs
Scopus | 84959517592 |
---|---|
WOS | 000372022800004 |
Keywords
Keywords
- FROZEN GAUSSIAN APPROXIMATION, VALUE SERIES REPRESENTATION, THERMAL RATE CONSTANTS, HYBRID APPROACH, DYNAMICS, SPECTRA, ABSORPTION, MOLECULES