A. J. C. Varandas and H. G. Yu
A time-dependent wavepacket method for including geometric phase (GP) effects in hyperspherical coordinates is given. It uses the hybrid basis/grid representation and prime-factor fast Fourier transformation (PFFT) technique to propagate a wavepacket while the GP effects are treated on the fly using the method of Billing and Marković (J. Chem. Phys., 1993, 99, 2674). The calculated vibrational states of the first electronically excited H3 molecule with and without GP effects are found to be significantly different and in excellent agreement with previous theoretical investigations. In contrast, GP effects on transition-state resonances of ground-state H3 are minor, although some notable differences can be observed in the autocorrelation functions after 90 fs wavepacket propagation.