The Quantum Trajectory-quided Adaptive Gaussian Methodology in the Libra
Software Package
Abstract
In this account we report an implementation of the quantum
trajectory-guided adaptive Gaussian (QTAG) method in a modular
open-source Libra package for quantum dynamics calculations. The QTAG
method is based on a representation of wavefunctions in terms of a
quantum trajectory-guided adaptable Gaussians basis and is generalized
for time-propagation on multiple coupled surfaces to be applicable to
model nonadiabatic dynamics. The potential matrix elements are evaluated
within either the local harmonic or bra-ket-average (linear)
approximations to the potential energy surfaces, the latter being a more
practical option. Performance of the QTAG method is demonstrated and
discussed for the Holstein and Tully models, which are the standard
benchmarks for method development in the area of nonadiabatic dynamics.