What is WDYN Program Package?
- WDYN implements a quasi-classical Wigner method (WQC) for approximate quantum dynamics and calculations of quantum autocorrelation function. The Fourier transform of the autocorrelation function gives the Franck-Condon overlaps between the initial wavefunction and the vibrational eigenstates of the system.
- WDYN approximate quantum dynamical simulations are suitable for molecular systems up to ten or more dimensions (see also below).
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WDYN can be used for calculations of high resolution
UV/VIS spectra in two ways:
- Simulations of line positions and intensities. This is possible only for cases where population of excited vibrational levels prevails.
- Calculation of line positions without intensities. This is possible for either case.
- WDYN is suitable for precise studies of IR spectra.
- WDYN is well suited even for strongly unharmonic systems including chaotic systems.
- WDYN does not include deep quantum effects (tunelling).
- WDYN calculations are based on a pair-wise molecular potential.
In the last decades, quantum‑chemical tools attacked almost all areas of applied chemistry and spectroscopy. An important development of quantum‑dynamical methods came along with femtosecond chemistry, which allowed to monitor nuclear dynamics directly via pump‑probe experiments. At the same time, the quantum‑dynamical methods started to be used to model the time‑independent vibrationally resolved electronic spectra associated with the dynamics.
